Genomic Analysis of Multidrug-Resistant Escherichia coli Strains Isolated in Tamaulipas, Mexico.

The global spread of antimicrobial resistance genes (ARGs) is a major public health concern. Mobile genetic elements (MGEs) are the main drivers of this spread by horizontal gene transfer (HGT). Escherichia coli is widespread in various environments and serves as an indicator for monitoring antimicrobial resistance (AMR). Therefore, the objective of this work was to evaluate the whole genome of multidrug-resistant E. coli strains isolated from human clinical, animal, and environmental sources. Four E. coli strains previously isolated from human urine (n = 2), retail meat (n = 1), and water from the Rio Grande River (n = 1) collected in northern Tamaulipas, Mexico, were analyzed. E. coli strains were evaluated for antimicrobial susceptibility, followed by whole genome sequencing and bioinformatic analysis. Several ARGs were detected, including blaCTX-M-15, blaOXA-1, blaTEM-1B, blaCMY-2, qnrB, catB3, sul2, and sul3. Additionally, plasmid replicons (IncFIA, IncFIB, IncFII, IncY, IncR, and Col) and intact prophages were also found. Insertion sequences (ISs) were structurally linked with resistance and virulence genes. Finally, these findings indicate that E. coli strains have a large repertoire of resistance determinants, highlighting a high pathogenic potential and the need to monitor them.

Extended-Spectrum ß-Lactamase-Producing Escherichia coli Isolated from Food-Producing Animals in Tamaulipas, Mexico.

Extended-spectrum ß-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.

Molecular and Antimicrobial Susceptibility Characterization of Escherichia coli Isolates from Bovine Slaughterhouse Process.

Antimicrobials are routinely used in human and veterinary medicine. With repeated exposure, antimicrobials promote antibiotic resistance, which poses a threat to public health. In this study, we aimed to determine the susceptibility patterns, virulence factors, and phylogroups of E. coli isolates during the killing process in a bovine slaughterhouse. We analyzed 336 samples (from water, surfaces, carcasses, and feces), and 83.3% (280/336) were positive for E. coli. The most common phenotypic resistances that we detected were 50.7% (142/280) for tetracycline, 44.2% (124/280) for cephalothin, 34.6% (97/280) for streptomycin, and 36.7% (103/280) for ampicillin. A total of 82.4% of the isolates had resistance for at least one antimicrobial, and 37.5% presented multiresistance. We detected a total of 69 different phenotypic resistance patterns. We detected six other resistance-related genes, the most prevalent being tetA (22.5%) and strB (15.7%). The prevalence values of the virulence genes were 5.4% in hlyA, 1.4% in stx1, and 0.7% in stx2. The frequencies of the pathogenic strains (B2 and D) were 32.8% (92/280) and 67.1% (188/280) as commensals A and B1, respectively. E. coli isolates with pathogenic potential and multiresistance may represent an important source of dissemination and a risk to consumers.

Evaluation of Retail Meat as a Source of ESBL Escherichia coli in Tamaulipas, Mexico.

In recent decades, the appearance of a group of strains resistant to most ß-lactam antibiotics, called extended-spectrum ß-lactamases (ESBLs), has greatly impacted the public health sector. The present work aimed to identify the prevalence of ESBL-producing Escherichia coli strains in retail meat from northeast Tamaulipas. A total of 228 meat samples were obtained from 76 different stores. A prevalence of E. coli ESBL of 6.5% (15/228) was detected. All (15/15) of the ESBL strains were multiresistant. Altogether, 40% (6/15) of the strains showed the presence of class 1 integrons. The isolates identified with blaCTX-M (20%) also showed co-resistance with the tet (A and B), str (A and B), and sul (2 and 3) genes. A total of 20% of the strains belonged to the B2 and D phylogroups, which are considered pathogenic groups. None of the ESBL-positive strains contained any of the virulence gene factors tested. The presence of ESBL-producing E. coli strains in meat indicates a potential risk to the consumer. Although most of these strains were classified as commensals, they were found to serve as reservoirs of multiresistance to antimicrobials and, therefore, are potential routes of dispersion of this resistance to other bacteria.

Characterization of triatomine bloodmeal sources using direct Sanger sequencing and amplicon deep sequencing methods.

Knowledge of host associations of blood-feeding vectors may afford insights into managing disease systems and protecting public health. However, the ability of methods to distinguish bloodmeal sources varies widely. We used two methods-Sanger sequencing and amplicon deep sequencing-to target a 228 bp region of the vertebrate Cytochrome b gene and determine hosts fed upon by triatomines (n = 115) collected primarily in Texas, USA. Direct Sanger sequencing of PCR amplicons was successful for 36 samples (31%). Sanger sequencing revealed 15 distinct host species, which included humans, domestic animals (Canis lupus familiaris, Ovis aries, Gallus gallus, Bos taurus, Felis catus, and Capra hircus), wildlife (Rattus rattus, Incilius nebulifer, Sciurus carolinensis, Sciurus niger, and Odocoileus virginianus), and captive animals (Panthera tigris, Colobus spp., and Chelonoidis carbonaria). Samples sequenced by the Sanger method were also subjected to Illumina MiSeq amplicon deep sequencing. The amplicon deep sequencing results (average of 302,080 usable reads per sample) replicated the host community revealed using Sanger sequencing, and detected additional hosts in five triatomines (13.9%), including two additional blood sources (Procyon lotor and Bassariscus astutus). Up to four bloodmeal sources were detected in a single triatomine (I. nebulifer, Homo sapiens, C. lupus familiaris, and S. carolinensis). Enhanced understanding of vector-host-parasite networks may allow for integrated vector management programs focusing on highly-utilized and highly-infected host species.

Azospirillum spp. from Plant Growth-Promoting Bacteria to Their Use in Bioremediation.

Xenobiotic contamination, a worldwide environmental concern, poses risks for humans, animals, microbe health, and agriculture. Hydrocarbons and heavy metals top the list of toxins that represent a risk to nature. This review deals with the study of Azospirillum sp., widely reported as plant growth-promoting bacteria in various cultures. However, its adaptation properties in adverse environments make it a good candidate for studying remediation processes in environments polluted with hydrocarbons and heavy metals. This review includes studies that address its properties as a plant growth promoter, its genomics, and that evaluate its potential use in the remediation of hydrocarbons and heavy metals.

Draft Genome Sequence of a Uropathogenic Escherichia coli Sequence Type 44 Strain Carrying Multiple Antimicrobial Resistance Genes.

Escherichia coli is a reservoir of antimicrobial resistance genes (ARGs). Here, we report the draft genome sequence of an E. coli strain (31HGR-CBG) that was isolated from a urine sample in Tamaulipas, Mexico. 31HGR-CBG harbors multiple ARGs, including blaCTX-M-15 and class 1 integron. This strain also carries multiple virulence genes.

RDRioMycobacterium tuberculosis strains associated with isoniazid resistance in Northern Mexico.

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 Löwenstein-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.

RDRioMycobacterium tuberculosis strains associated with isoniazid resistance in Northern Mexico / Identificación del genotipo Mycobacterium tuberculosis RDRio en el norte de México y su asociación con la resistencia a isoniazida

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 Löwenstein-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.(AU)

Introducción: El genotipo de Mycobacteriumtuberculosis podría influir en la fisiopatología y la evolución de la tuberculosis, en particular los genotipos Beijing y LAM/RDRio. El propósito de este estudio fue evaluar la prevalencia del genotipo LAM/RDRio en casos de tuberculosis pulmonar en México y determinar su perfil de sensibilidad a los fármacos antituberculosos. Métodos: Se evaluaron 218 cepas de M. tuberculosis mediante spoligotyping. El genotipo LAM/RDRio se confirmó mediante PCR múltiple. Las pruebas de sensibilidad a fármacos antituberculosos se realizaron en medio sólido de Löwenstein-Jensen. Resultados: Entre las cepas LAM identificadas, 24 (63,1%) fueron confirmadas como M. tuberculosis RDRio y se asociaron significativamente con resistencia a isoniazida (p = 0,0264). Todos los aislamientos RDRio presentaron la deleción del locus RD174. Conclusión: En este estudio documentamos por primera vez el aislamiento del genotipo RDRio en casos de tuberculosis pulmonar en México, encontrando una asociación estadísticamente significativa entre este genotipo y la resistencia a isoniazida.(AU)

Advances in Control Strategies against Spodoptera frugiperda. A Review.

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.

Identification and Characterization of the CRISPR/Cas System in Staphylococcus aureus Strains From Diverse Sources.

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.

Virtual Screening of FDA-Approved Drugs against Triose Phosphate Isomerase from Entamoeba histolytica and Giardia lamblia Identifies Inhibitors of Their Trophozoite Growth Phase.

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).

Multidrug Resistance of Escherichia coli Strains Isolated From Bovine Feces and Carcasses in Northeast Mexico.

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 ß-lactamase (bla TEM and bla SHV) 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 bla TEM and bla SHV 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.

Recent Advances in the Development of Broad-Spectrum Antiprotozoal Agents.

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.

RDRioMycobacterium tuberculosis strains associated with isoniazid resistance in Northern Mexico.

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 Löwenstein-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.

In Silico Analysis of FDA Drugs as P2X4 Modulators for the Treatment of Alcohol Use Disorder.

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.

Analysis of the effect of methyl 2-acetamide-3-methylquinoxaline-7-carboxylate 1,4-di-N-oxide on the relative expression of the trypanothione reductase gene in Trypanosoma cruzi epimastigotes.

In recent decades, some quinoxaline 1,4-di-N-oxide derivatives have been shown to have better trypanocidal activity than the reference drugs; however, their mechanism of action is not yet clear, although it is suggested that they mainly produce reactive oxygen species that cause oxidative stress and parasite death. Trypanosoma cruzi relies on the enzyme trypanothione reductase, among others, to defend itself against oxidative stress. With the aim of contributing to the elucidation of the mechanism of action of quinoxaline 1,4-di-N-oxide derivatives on Trypanosoma cruzi, this study was carried out to evaluate the effect of methyl 2-amide-3-methylquinoxaline-7-carboxylate 1,4-di-N-oxide (compound M-8) on the expression of the trypanothione reductase gene in an in vitro model on Trypanosoma cruzi epimastigotes of the CL-Brener strain. The results show that compound M-8 does not cause a significant effect on the trypanothione reductase gene, suggesting a mechanism of action not related to oxidative stress.

Effect of 4-amino-3-nitrobenzoic acid on the expression level of the trans-sialidase gene in Trypanosoma cruzi epimastigotes.

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.

Structure-Based Virtual Screening and In Vitro Evaluation of New Trypanosoma cruzi Cruzain Inhibitors.

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.

Frequency of the L1014F Mutation in the Sodium Channel Gene, in Culex quinquefasciatus (Diptera: Culicidae) Populations From Rural and Urban Areas of Yucatan State, Mexico.

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.