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Microbial communities are known to play a principal role in petroleum degradation. This study tries to determine the composition of bacteria in selected crude oil-contaminated soil from Tabasco and Tamaulipas states, Mexico. We determined the microbial populations living under these conditions. We evaluated the structure and diversity of bacterial communities in the contaminated soil samples. The most abundant phylum is proteobacteria. Next Generation Sequencing (NGS) analysis of the sampled soils from both states revealed that this phylum has the most relative abundance among the identified bacteria phyla. The heatmap represented the relative percentage of each genus within each sample and clustered the four samples into two groups. Moreover, this allowed us to identify many genera in alkaline soil from Tamaulipas, such as Skermanella sp., Azospirillum sp. and Unclassified species from the Rhodospirillaceae family in higher abundance. Meanwhile, in acidic soil from Tabasco, we identified Thalassospira, Unclassified members of the Sphingomonadaceae family and Unclassified members of the Alphaproteobacteria class with higher abundance. Alpha diversity analysis showed a low diversity (Shannon and Simpson index); Chao observed species in both Regions. These results suggest that the bacteria identified in these genera may possess the ability to degrade petroleum, and further studies in the future should elucidate their role in petroleum degradation.

Extended-spectrum β-lactamase (ESBL)-producing E. coli has become an important global problem for the public health sector. This study aims to investigate the E. coli antimicrobial resistance profile among living food-producing animals in Tamaulipas, Mexico. A total of 200 fecal samples were collected from bovines, pigs, chickens and sheep. A total of 5.0% of the strains were phenotypically confirmed as ESBL producers. A high percentage of phenotypic antimicrobial resistance was observed against gentamicin (93.3%), tetracycline (86.6%) and streptomycin (83.3%). The gentamicin-resistant strains showed MDR, distributed among 27 resistance patterns to different antimicrobials. The antimicrobial resistance gene tet(A) was detected in 73.3% of isolates, aadA1 in 60.0% and sul2 in 43.3% of strains. The blaCTX-M gene was found in 23.3% of strains. The virulence gene hlyA was detected in 43.3% of isolates; stx1 and stx2 were not detected in any strain. The phylotyping indicated that the isolates belonged to groups A (33.3%), B1 (16.6%), B2 (40.0%) and D (10.0%). These results show that food-producing animals might be a reservoir of ESBL-producing bacteria and may play a role in their spread.

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

Infections caused by Trypanosoma brucei, Trypanosoma cruzi, Leishmania spp., Entamoeba histolytica, Giardia lamblia, Plasmodium spp., and Trichomonas vaginalis, are part of a large list of human parasitic diseases. Together, they cause more than 500 million infections per year. These protozoa parasites affect both low- and high-income countries and their pharmacological treatments are limited. Therefore, new and more effective drugs in preclinical development could improve overall therapy for parasitic infections even when their mechanisms of action are unknown. In this review, a number of heterocyclic compounds (diamidine, guanidine, quinoline, benzimidazole, thiazole, diazanaphthalene, and their derivatives) reported as antiprotozoal agents are discussed as options for developing new pharmacological treatments for parasitic diseases.

Background: Giardiasis is an important public health problem. However, its pharmacological treatment is limited mainly to two drugs, metronidazole and nitazoxanide. Objectives: Screening four series of esters (methyl, ethyl, isopropyl and n-propyl) of quinoxaline-7- carboxylate 1,4-di-N-oxide in in vitro and in vivo models as antigiardiasis agents. Objectives: Screening four series of esters (methyl, ethyl, isopropyl and n-propyl) of quinoxaline-7- carboxylate 1,4-di-N-oxide in in vitro and in vivo models as antigiardiasis agents. Methods: Briefly, 4 × 104 trophozoites of G. lamblia were incubated for 48 h at 37 °C with different concentrations of esters of quinoxaline-7-carboxylate 1,4-di-N-oxide, albendazole, metronidazole and nitazoxanide. Afterwards, trophozoites were counted and the half maximal inhibitory concentration (IC50) was calculated by Probit analysis. The in vivo antigiardial activity of the compounds was demonstrated using experimental infections of G. lamblia in suckling female CD-1 mice. Results: Compound T-069 with a thienyl, a trifluoromethyl and an isopropyl group at R1-, R2- and R3-position, respectively, on the quinoxaline 1,4-di-N-oxide ring in an in vitro model showed an IC50 value of 0.0014 µM, and 3502 and 1108 times more giardicidal activity than nitazoxanide and metronidazole in an in vivo model. Conclusion: Isopropyl ester of quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives showed better giardicidal activity than the reference drugs; therefore, these compounds are good candidates to develop new pharmacological treatment for giardiasis.

Background: Stenotrophomonas species are multi-resistant bacteria with ability to cause opportunistic infections. Objective: We isolated 45 Stenotrophomonas species from soil, sewage and the clinic with the aim of investigating their susceptibility to commonly used antimicrobial agents. Methodology: The identities of isolates were confirmed with 16S rRNA gene sequence and MALDI-TOF analysis. Anti-mi- crobial resistance, biofilm production and clonal diversity were also evaluated. The minimum inhibitory concentration technique as described by Clinical & Laboratory Standards Institute: CLSI Guidelines (CLSI) was employed for the evaluation of isolate susceptibility to antibiotics. Result: Forty-five Stenotrophomonas species which include 36 environmental strains and 9 clinical strains of S. maltophilia were considered in this study. 32 (88.9 %) environmental strains were identified to be S. maltophilia, 2 (5.6 %) were Stenotrophomonas nitritireducens, and 2 (5.6 %) cluster as Stenotrophomonas spp. Stenotrophomonas isolates were resistant to at least six of the antibiotics tested, including Trimethoprim/Sulfamethoxazole (SXT). Conclusion: Environmental isolates from this study were resistant to SXT which is commonly used for the treatment of S. maltophilia infections. This informs the need for good public hygiene as the environment could be a reservoir of multi-resistant bacteria. It also buttresses the importance of surveillance study in the management of bacterial resistance. Keywords: Stenotrophomonas; environmental; biochemical characterization; clonal diversity; anti-microbial susceptibility.

The strategies for controlling the insect pest Spodoptera frugiperda have been developing over the past four decades; however, the insecticide resistance and the remarkable adaptability of this insect have hindered its success. This review first analyzes the different chemical compounds currently available and the most promising options to control S. frugiperda. Then, we analyze the metabolites obtained from plant extracts with antifeedant, repellent, insecticide, or ovicide effects that could be environmentally friendly options for developing botanical S. frugiperda insecticides. Subsequently, we analyze the biological control based on the use of bacteria, viruses, fungi, and parasitoids against this pest. Finally, the use of sex pheromones to monitor this pest is analyzed. The advances reviewed could provide a wide panorama to guide the search for new pesticidal strategies but focused on environmental sustainability against S. frugiperda.

Diversos microorganismos han sido reportados por su eficacia en la biodegradación de contaminantes como plaguicidas gracias a sus características metabólicas. En este estudio, se aislaron e identificaron bacterias de suelos agrícolas las cuales mostraron ser capaces de tolerar pesticidas y utilizarlos como única fuente de carbono y energía. Se evaluaron cinco pesticidas más comúnmente utilizados (sales dimetilaminas, tri-isopropanolaminas y de glifosato, atrazina y carbofuran) a diferentes concentraciones utilizando dos medios de cultivo: TY (Triptona / Extracto de Levadura) y Bushnell Haas (FLUKA). Del medio TY se obtuvieron 13 aislados los cuales toleraron 0.05%, 1, 5 y 10% v/v de la concentración de los pesticidas en el medio de cultivo. Los aislados que toleraron 1% v/v de glifosato y sales dimetilaminas fueron identificados como Bacillus, Microbacterium y Bordetella, mientras que los que toleraron 5 y 10% v/v de sales tri-isopropanolaminas, atrazina y carbofuran en el medio de cultivo corresponden a los géneros Pseudomonas, Enterobacter, Stenotrophomonas y Achromobacter. Por otro lado, al utilizar el medio Bushnell Haas se obtuvieron 9 aislamientos que toleraron concentraciones de 0.05% y 0.5% v/v para el glifosato, 2.5% v/v para sales dimetilaminas, 5% v/v para atrazina y carbofuran. Estos corresponden a los géneros Pseudomonas, Stenotrophomonas, Brevundimonas, Achromobacter y Enterobacter.

Las infecciones de pie diabético (IPD) son un problema de salud mundial. En México, 128 mil amputaciones se llevaron a cabo por pie diabético en el 2016, generando altos costos económicos. Esto debido en parte a que la identificación de las bacterias en las IPD es un proceso que puede llevar varios días por métodos microbiológicos, además, podrían generar un sesgo ya que los agentes patógenos podrían no ser identificados en su totalidad. Adicionalmente, los cultivos se enfocan generalmente al estudio de bacterias aerobias, dejando de lado el grupo de anaerobios, por lo cual su papel en estas infecciones es controversial. Los métodos moleculares permiten la detección indirecta de las bacterias anaerobias, de modo que es posible estimar su prevalencia. El objetivo de este trabajo fue detectar la presencia de Bacteroides fragilis en biopsias de infecciones de pie diabético mediante PCR. El 11.6% de las muestras resultaron positivas lo que indica que existe una prevalencia relevante de esta bacteria en dichas infecciones, de modo que podría tomar parte en el desarrollo de dichas infecciones y representar un riesgo para los pacientes.

Los patógenos en aire pueden afectar la salud humana, no solo por infecciones, sino causando respuestas alérgicas o efectos tóxicos. Estos microorganismos pueden encontrar un ambiente ideal de desarrollo en unidades de aire acondicionado y aunque existen innovaciones para un flujo de aire más limpio y saludable, usuarios en países en desarrollo tienen modelos anteriores o carecen de una rutina de limpieza adecuada de filtros empleados, representando un peligro para poblaciones vulnerables que pasan mucho tiempo en ambientes climatizados. Por esto, nuestro objetivo fue detectar mediante métodos microbiológicos y moleculares la presencia de patógenos en muestras de Tamaulipas, México. Nuestros hallazgos muestran una carga bacteriana media superando las 2,300,000 UFC (unidades formadoras de colonia) /g, β-hemólisis en más del 20% de los cultivos en agar sangre, crecimiento en medios selectivos para Staphylococcus sp. y Enterobacteriaceae en más del 50% de las muestras, esta última confirmada por ensayos moleculares, los cuales también mostraron una baja prevalencia de genes relacionados con resistencia a antibióticos. Estos resultados nos indican que el polvo acumulado en las rejillas de aires acondicionados puede efectivamente ser reservorio de bacterias con capacidad patogénica

The CRISPR-Cas [clustered regularly interspaced short palindromic repeats and the CRISPR-associated genes (Cas)] system provides defense mechanisms in bacteria and archaea vs. mobile genetic elements (MGEs), such as plasmids and bacteriophages, which can either be harmful or add sequences that can provide virulence or antibiotic resistance. Staphylococcus aureus is a Gram-positive bacterium that could be the etiological agent of important soft tissue infections that can lead to bacteremia and sepsis. The role of the CRISPR-Cas system in S. aureus is not completely understood since there is a lack of knowledge about it. We analyzed 716 genomes and 1 genomic island from GENOMES-NCBI and ENA-EMBL searching for the CRISPR-Cas systems and their spacer sequences (SSs). Our bioinformatic analysis shows that only 0.83% (6/716) of the analyzed genomes harbored the CRISPR-Cas system, all of them were subtype III-A, which is characterized by the presence of the cas10/csm1 gene. Analysis of SSs showed that 91% (40/44) had no match to annotated MGEs and 9% of SSs corresponded to plasmids and bacteriophages, indicating that those phages had infected those S. aureus strains. Some of those phages have been proposed as an alternative therapy in biofilm-forming or infection with S. aureus strains, but these findings indicate that such antibiotic phage strategy would be ineffective. More research about the CRISPR/Cas system is necessary for a bigger number of S. aureus strains from different sources, so additional features can be studied.

8 p.-3 fig.-1 tab., Infectious diseases caused by intestinal protozoan, such as Entamoeba histolytica (E. histolytica) and Giardia lamblia (G. lamblia) are a worldwide public health issue. They affect more than 70 million people every year. They colonize intestines causing primarily diarrhea; nevertheless, these infections can lead to more serious complications. The treatment of choice, metronidazole, is in doubt due to adverse effects and resistance. Therefore, there is a need for new compounds against these parasites. In this work, a structure-based virtual screening of FDA-approved drugs was performed to identify compounds with antiprotozoal activity. The glycolytic enzyme triosephosphate isomerase, present in both E. histolytica and G. lamblia, was used as the drug target. The compounds with the best average docking score on both structures were selected for the in vitro evaluation. Three compounds, chlorhexidine, tolcapone, and imatinib, were capable of inhibit growth on G. lamblia trophozoites (0.05–4.935 μg/mL), while folic acid showed activity against E. histolytica (0.186 μg/mL) and G. lamblia (5.342 μg/mL)., This research was funded by the Secretaria de Investigación y Posgrado del Instituto Politécnico Nacional, grant number 20210050.

Infectious diseases caused by intestinal protozoan, such as Entamoeba histolytica (E. histolytica) and Giardia lamblia (G. lamblia) are a worldwide public health issue. They affect more than 70 million people every year. They colonize intestines causing primarily diarrhea; nevertheless, these infections can lead to more serious complications. The treatment of choice, metronidazole, is in doubt due to adverse effects and resistance. Therefore, there is a need for new compounds against these parasites. In this work, a structure-based virtual screening of FDA-approved drugs was performed to identify compounds with antiprotozoal activity. The glycolytic enzyme triosephosphate isomerase, present in both E. histolytica and G. lamblia, was used as the drug target. The compounds with the best average docking score on both structures were selected for the in vitro evaluation. Three compounds, chlorhexidine, tolcapone, and imatinib, were capable of inhibit growth on G. lamblia trophozoites (0.05–4.935 μg/mL), while folic acid showed activity against E. histolytica (0.186 μg/mL) and G. lamblia (5.342 μg/mL).

In this work, the antimicrobial resistance profile of Escherichia coli strains (n = 248) isolated from bovine feces and carcass samples from Tamaulipas, Mexico, was evaluated. Susceptibility to 12 antibiotics conventionally used in human and veterinary treatments was determined according to Clinical and Laboratory Standards Institute guidelines. Genes encoding resistance to tetracycline (tetA and tetB), streptomycin (strA), aminoglycoside (aadA), and β-lactamase (blaTEM and blaSHV) were investigated by PCR. Also, stx1, stx2, eae, bfp, and hlyA encoding virulence factors were determined. Of the isolates, 85.9% were confirmed as E. coli strains. Among the 213 E. coli isolates tested, 94.8% (202/213) showed resistance for at least one antimicrobial, mainly ampicillin (83.0%; 177/213), cephalothin (76.0%; 162/213), and tetracyclines (69.0%; 147/213). In all the other antibiotics tested, the resistance percentage was below 36%. A multidrug-resistant phenotype was found in 72.7% of the tested strains. The presence of the tet gene (tetA or tetB) was detected in 43.1% of the isolates, the strA gene in 17.3%, and aadA1 in 51.6%. The blaTEM and blaSHV genes were found in 10.3 and 0.4% of the isolates, respectively. stx1 was detected in 4.2% of isolates, stx2 in 7.0, and hlyA in 2.8%. The virulence genes, eae and bfp, were not detected in any strain. These results indicate that Tamaulipas food products of bovine origin can be a source of multiresistant E. coli strains for the environment and exposure for consumers.

Purpose Among the principal microorganisms transmitted to humans by foods of animal origin, Staphylococcus aureus stands out, causing a variety of diseases and with a wide potential for acquiring antimicrobial resistance. This work aimed to determine the prevalence of S. aureus, its multi-drug resistance (MDRSA), and the identification of methicillin-resistant Staphylococcus aureus (MRSA) in retail beef and pork in the state of Tamaulipas, Mexico. Methods S. aureus strains isolated from retail meat were characterized by microbiological and molecular methods to determine phenotypic drug-resistance and detect MRSA strains. Results Of the 106 samples (54 from beef and 52 from pork) from 11 different cities, we detected a prevalence of S. aureus of 44.3% (47/106). A total of 87 S. aureus strains were identified; these presented 54 resistance patterns to different antimicrobials with a high prevalence of MDRSA (85%) and a low prevalence of MRSA strains (3%). Conclusion These results indicate the presence of MDRSA and MRSA in retail beef and pork in Tamaulipas, representing a high risk for consumer health.

The development of novel bioremediation strategies has focused on the isolation and identification of microorganisms that can thrive in polluted environments to evaluate their potential as biotechnological tools in bioremediation techniques. In this work, a bacterium isolated from hydrocarbon-contaminated soils from the Burgos basin was identified and its hydrocarbon degradation potential was evaluated. Identification based on sequencing the 16S rRNA gene identified one of the isolates (R3) as Microbacterium petrolearium. This strain was mainly antibiotic-sensitive with elevated carbohydrate assimilation differing from previously reported strains. Moderate surfactant production (I24 = 22.97 %) was observed, which was absent in a cell-free extract. M. petrolearium R3 showed increased growth that correlated with pollutant concentration. For light crude oil, at a higher contaminant percentage, the R3 strain showed increased growth; however, in the case of diesel, no growth was detected. The aforementioned data indicate that M. petrolearium strain R3, isolated from local sources, has potential use as a tool for hydrocarbon-contaminated soil bioremediation.

Background Stenotrophomonas species are multi-resistant bacteria with ability to cause opportunistic infections Objective We isolated 45 Stenotrophomonas species from soil, sewage and the clinic with the aim of investigating their susceptibility to commonly used antimicrobial agents. Methodology The identities of isolates were confirmed with 16S rRNA gene sequence and MALDI-TOF analysis. Anti-microbial resistance, biofilm production and clonal diversity were also evaluated. The minimum inhibitory concentration technique as described by Clinical & Laboratory Standards Institute: CLSI Guidelines (CLSI) was employed for the evaluation of isolate susceptibility to antibiotics. Result Forty-five Stenotrophomonas species which include 36 environmental strains and 9 clinical strains of S. maltophilia were considered in this study. 32 (88.9 %) environmental strains were identified to be S. maltophilia, 2 (5.6 %) were Stenotrophomonas nitritireducens, and 2 (5.6 %) cluster as Stenotrophomonas spp. Stenotrophomonas isolates were resistant to at least six of the antibiotics tested, including Trimethoprim/Sulfamethoxazole (SXT). Conclusion Environmental isolates from this study were resistant to SXT which is commonly used for the treatment of S. maltophilia infections. This informs the need for good public hygiene as the environment could be a reservoir of multi-resistant bacteria. It also buttresses the importance of surveillance study in the management of bacterial resistance.

Production of extended spectrum beta-lactamases (ESBL) is one of the main problems related to antimicrobial resistance worldwide, with the CTX-M, TEM and SHV types standing out as the most prevalent. These enzymes are usually related to plasmids which facilitates their horizontal genetic transmission. In the northeast region of Tamaulipas their clinical prevalence is unknown. Therefore, the aim of this work was to define the molecular epidemiology of ESBL-producing Enterobacteriaceae in clinical strains collected in Reynosa Tamaulipas, Mexico. A selection of 123 Enterobacteriaceae strains from different clinical patients were collected from August 2018 to December 2019. These strains were phenotypically identified by double disk synergy tests (DDST) and subsequently subjected to polymerase chain reaction for the detection and amplification of the blaTEM, blaSHV, blaCTX−M−1, blaCTX−M−2, blaCTX−M−9 and blaCTX−M−8/25 genes. Lastly, antimicrobial resistance profiles were determined by plate diffusion method and their capacity to transfer this sort of resistance by conjugation was assessed. Our results showed a prevalence of 48.78% (60/123) of ESBL-producing enterobacteria, with the blaTEM and blaCTX−M−1 genes most commonly detected in 76.67% (46/60) and 58.33% (35/60), respectively. Additionally, a 68.33% (41/60) of these ESBL-producing Enterobacteriaceae were multidrug-resistant, while 51.67% (31/60) were able to transfer some genes related to ESBL production, being blaCTX−M−1 the most common. This is the first study in the region that evaluates ESBL production in clinical Enterobacteriaceae strains, as well as the content of genes related to this phenotype and the ability to transfer this type of antimicrobial resistance.

It has been established that the genomic background of Mycobacterium tuberculosis may influence disease progression, in particular for the Beijing family and the Latin American and Mediterranean (LAM)/RDTwo hundred eighteen M. tuberculosis isolates were screened by 43-spacer spoligotyping. The LAM/RDAmong the LAM strains identified, 24 (63.1%) were confirmed as M. tuberculosis RDWe documented for the first time the isolation of the LAM/RD

Objectives The aim of this study was to determinate the prevalence of Escherichia coli and its resistance to antimicrobials and the presence of virulence genes in retail samples of beef and pork in several locations in Tamaulipas, Mexico. Methods A total of 106 samples (54 beef and 52 pork) collected from August 2013 to March 2014 were analysed to detect E. coli isolates. The E. coli isolates were then analysed for detection of virulence factors and antimicrobial resistance genes. Antimicrobial susceptibility to 16 antimicrobial agents was also determined. Results A total of 158 E. coli isolates were obtained, among which 3 (1.9%) harboured the virulence gene stx1, 28 (17.7%) harboured stx2 and 34 (21.5%) harboured hlyA. High phenotypic resistance was observed in almost all isolates, since 146 (92.4%) showed a multiresistant phenotype with resistance to cefalotin (92%), ampicillin (92%), cefotaxime (78%), nitrofurantoin (76%) and tetracycline (75%). The antimicrobial resistance genes tet(A) and tet(B) were detected in 56% of isolates, strA in 9.6%, aadA in 17% and aac(3)-IV in only 0.6% of strains. Conclusions Based on these results, it can be concluded that retail beef and pork meat may play a role in the spread of antimicrobial-resistant E. coli strains in this region.

Culex quinquefasciatus Say (Diptera: Culicidae) is a mosquito species that has attracted a lot of attention from a medical and veterinary point of view; however, little is known about the frequency of L1014F mutations that have been found in the sodium channel gene, with this being a target for DDT and pyrethroid insecticides. The distribution and frequency of the L1014F mutation in Cx. quinquefasciatus populations was determined in rural and urban areas of Yucatan, Mexico from January 2015 to March 2016. Nine hundred fifty adult females out of 17,727 immature states were collected and analyzed in all sites sampled (n = 10). Susceptible homozygotes were identified (L1014/L1014) in 12% (114/950), heterozygous individuals (F1014/L1014) in 34% (323/950), and mutated homozygotes (F1014/F1014) in 54% (513/950) during the dry and rainy seasons. In this work, study areas with a high frequency of L1014F mutation were identified. These findings may help guarantee a more effective and efficient use of the resources available for the control of this vector.

El objetivo de este trabajo fue determinar la presencia de genes de virulencia en cepas de E. coli aisladas del Río Bravo en la ciudad de Reynosa Tamaulipas. Mediante la técnica de PCR se realizó la detección de los genes que codifican para factores de virulencia como son eae, bfp, stx1 y stx2 en muestras de aguas superficiales del Río Bravo en el municipio de Reynosa Tamaulipas y se identificó que el gen stx2 (27%) fue el más prevalente, seguido de stx1 (10%). Aunque el resto de las muestras fueron consideradas comensales al no tener ninguno de los genes propuestos, la presencia de genes stx1 y stx2 son considerados como un riesgo a la población que tiene contacto con el agua superficial del Río Bravo, por lo cual es necesario un monitoreo microbiológico en esta zona.

The Rio Bravo (Rio Grande) adjoins various states in the Mexican region and has a great importance in water distribution in the northeast Tamaulipas (Mexico). In this work 161 strains were isolated, identified and characterized from the water samples taken from the flow of the Rio Bravo and the two inner canals that cover Reynosa city. The strains were identified as Vibrio cholerae (74·5%), Vibrio spp. (1·2%) and Vibrio mimicus (0·6%). Furthermore, the detected virulence genes in the V. cholerae strains, were the hlyA, ompU, tcpA, toxR genes in 78·3, 62·5, 15·8 and 90·8% respectively. Only the ompU and vmh genes were detected in the V. mimicus strain. These results indicate the presence of multi-toxigenic V. cholerae strains in the Rio Bravo/Grande and in the water bodies from Reynosa city, which could represent a risk for the exposed population. Significance and impact of the study Water quality is associated with public health, as it plays an important role in the transmission and epidemiology of pathogens such as Vibrio, since this species have been responsible for human diseases around the world. This study demonstrated the presence of toxigenic Vibrio species in water bodies in Reynosa surroundings, indicating that water bodies may be a source of public health risk.

Las amibas de vida libre (AVL) son protozoarios ampliamente distribuidos en el ambiente, aislados de una variedad de fuentes, incluyendo agua, suelo y polvo. Son considerados como patógenos desatendidos transmitidos por el agua, por su falta de estudio. Entre estos, Acanthamoeba spp. y Naegleria fowleri, las de interés para el presente estudio, son conocidas como agentes patogénicos y oportunistas de patologías severas. Más allá, estos organismos funcionan como “Caballo de Troya” para otras bacterias, hongos y virus patógenos para el humano, resistentes a su fagocitosis, lo cual representa un riesgo sanitario por su conocida resistencia a métodos de inactivación en agua. Actualmente, no existe información acerca de su distribución ambiental en el estado de Tamaulipas, es por ello por lo que el objetivo de este estudio fue evaluar la presencia de ellas mediante métodos de cultivo microbiológico. Su identificación se realizó a partir de características físicas observadas mediante inspección microscópica y los puntos de muestreo fueron evaluados para determinar la diversidad biológica y la presencia de otros organismos, debido a los altos niveles de contaminación observados. Los resultados revelaron que un 50% de los lugares muestreados fueron positivos para la presencia de Acanthamoeba spp.

Diabetic foot ulcers (DFUs) are a serious and common problem in patients with diabetes mellitus and constitute one of the major causes of lower extremity amputation. The microbiological profile of DFUs depends on the acute or chronic character of the wound. Aerobic gram-positive cocci are the predominant organisms isolated from DFUs. Diabetic foot biopsies from patients admitted to the Angiology and Vascular Surgery Hospital of the Northeast, in Reynosa, Tamaulipas from December 2011 to April 2016 were analyzed. The samples were processed using standard microbiology techniques. Antimicrobial susceptibility testing was carried out according to the protocol established by the Clinical & Laboratory Standards Institute (CLSI). We obtained 246 bacterial isolates, based on the results of phenotypic resistance. The least effective antibiotics for gram-positive bacteria were penicillin and dicloxacillin; for gram-negative bacteria, cefalotin and penicillin were the least effective. Levofloxacin, cefalotin, and amikacin were the most effective antibiotics for gram-positive and negative bacteria, respectively. Enterobacter genus was significantly associated with muscle biopsies ( P = .011) and samples without growth were significantly associated with specimens of pyogenic origin ( P = .000). In 215 DFU samples, we found that Staphylococcus aureus was the most commonly isolated pathogen followed by Enterobacter sp. This is consistent with previous reports. Enterobacter species may play an important role in the colonization/infection of certain tissues; however, further studies are needed in this regard.

Recent studies have shown the potential application of ivermectins in the treatment of alcohol use disorder (AUD). Ivermectin is a positive allosteric modulator (PAM) of P2X4R and this molecule exerts its action in the transmembrane region (known as the TM region) of trimeric channel structure (the pocket formed by Asp331, Met336, Trp46, Trp50, and Tyr42). The aim of this study is to identify FDA drugs with potential PAM properties, by exploring the P2X4Rs from four organisms (Danio rerio, Mus musculus, Rattus norvegicus, and Homo sapiens). The in silico study consists of carrying out the molecular docking of 1656 FDA-approved drugs on the structure of P2X4R, using the commercially available compounds from the ZINC15 database for virtual screening. To strengthen the reliability of the results, two docking protocols were used involving the use of two programs, Autodock 4.2 and Autodock Vina. Nine FDA drugs with potential PAM properties were identified. In addition, eight molecules with potential negative allosteric modulator (NAM) action, and 13 molecules with potential allosteric modulator (AM) action were identified. The FDA drugs identified in this study with PAM, NAM, and AM action, shared in the P2X4Rs of the four organisms, can provide a guideline to proceed with research concerning new drugs for the study and treatment of AUD.

Trans-sialidase of Trypanosoma cruzi (TcTS) is a key enzyme in the infection process from parasite to host; therefore, it has been considered an important target for developing new anti-Chagas drugs. Different compounds with trypanocidal activity and/or inhibition of TcTS have been reported; however, some benzoic acid derivatives have shown high enzymatic inhibition but low trypanocidal activity and viceversa. These results show that each compound may possess a different mechanism of action. Based on the above, the compound 4-amino-3-nitrobenzoic acid (16), a potent TcTS inhibitor (77% inhibition in enzymatic assays) was selected to evaluate its effects on the expression level of the TS gene in T. cruzi epimastigotes and determine its involvement in the mechanism of action. Results showed an increase in the expression level of the TcTS gene, which confirmed that compound 16, has a direct effect on TcTS.

Chagas disease (CD), or American trypanosomiasis, causes more than 10,000 deaths per year in the Americas. Current medical therapy for CD has low efficacy in the chronic phase of the disease and serious adverse effects, therefore, it is necessary to search for new pharmacological treatments. In this work, the ZINC15 database was filtered using the N-acylhydrazone moiety and a subsequent structure-based virtual screening was performed using the cruzain enzyme of Trypanosoma cruzi to predict new potential cruzain inhibitors. After a rational selection process, four compounds, Z2 (ZINC9873043), Z3 (ZINC9870651), Z5 (ZINC9715287), and Z6 (ZINC9861447), were chosen to evaluate their in vitro trypanocidal activity and enzyme inhibition. Compound Z5 showed the best trypanocidal activity against epimatigote (IC50 = 36.26 &plusmn, 9.9 &mu, M) and trypomastigote (IC50 = 166.21 &plusmn, 14.5 &mu, M and 185.1 &plusmn, 8.5 &mu, M on NINOA and INC-5 strains, respectively) forms of Trypanosoma cruzi. In addition, Z5 showed a better inhibitory effect on Trypanosoma cruzi proteases than S1 (STK552090, 8-chloro-N-(3-morpholinopropyl)-5H-pyrimido[5,4-b]-indol-4-amine), a known cruzain inhibitor. This study encourages the use of computational tools for the rational search for trypanocidal drugs.

Chagas disease (CD), or American trypanosomiasis, causes more than 10,000 deaths per year in the Americas. Current medical therapy for CD has low efficacy in the chronic phase of the disease and serious adverse effects; therefore, it is necessary to search for new pharmacological treatments. In this work, the ZINC15 database was filtered using the N-acylhydrazone moiety and a subsequent structure-based virtual screening was performed using the cruzain enzyme of Trypanosoma cruzi to predict new potential cruzain inhibitors. After a rational selection process, four compounds, Z2 (ZINC9873043), Z3 (ZINC9870651), Z5 (ZINC9715287), and Z6 (ZINC9861447), were chosen to evaluate their in vitro trypanocidal activity and enzyme inhibition. Compound Z5 showed the best trypanocidal activity against epimatigote (IC50 = 36.26 ± 9.9 μM) and trypomastigote (IC50 = 166.21 ± 14.5 μM and 185.1 ± 8.5 μM on NINOA and INC-5 strains, respectively) forms of Trypanosoma cruzi. In addition, Z5 showed a better inhibitory effect on Trypanosoma cruzi proteases than S1 (STK552090, 8-chloro-N-(3-morpholinopropyl)-5H-pyrimido[5,4-b]-indol-4-amine), a known cruzain inhibitor. This study encourages the use of computational tools for the rational search for trypanocidal drugs.