Multidrug resistance and class 1 integron presence in Escherichia coli isolates from a polluted drainage ditch's water.

The impact of contamination of water drainage ditches in the development of antibiotic-resistant bacteria has been scarcely studied in Mexico. In this regard, 101 isolates of E. coli were obtained from water samples from a ditch in Sinaloa, during one year. The antimicrobial resistant profiles, the presence of the class 1 integron and evolutionary relationship of intI1 sequences were determined. The 47.5% of strains were resistant and 5.9% multidrug resistant (MDR) with an average multiple antibiotic resistance index value of 0.45. The highest resistance was registered with ß-lactam (39.6%) and quinolone (9.9%). The intI1 gene was detected in 11.9% of the isolates, and no association with MDR was found. Sequence were associated with human and animal host isolates. MDR E. coli isolates with intI1 gene highlight the potential risk of the ditch's water to human health. An attenuation effect of MDR E. coli isolates in the outlet water was observed.

Effect of 4-hydroxychalcone as preventive and curative treatment in Wistar rats with liver injury.

The increasing prevalence and complications related to liver diseases (caused by infection, toxic agents, or metabolic syndrome), together with insufficient existence of treatments, make evident the need for better therapeutic alternatives. Therefore, the aim of this study was to determine the effect of 4-hydroxychalcone (4-HC) as preventive and curative treatment in acute and chronic liver injury, respectively. Liver damage was induced with carbon tetrachloride (CCl4) in Wistar rats. Rats were divided into two groups: (1) acute liver injury and (2) chronic liver injury. In turn, each group was divided into four subgroups: (i) control (water); (ii) dimethyl sulfoxide 10%; (iii) CCl4; and (iv) 4-HC. The pre-treatment with 4-HC decreased transaminases, IL-6 serum levels, and hepatic malondialdehyde, increased IL-10 serum levels and hepatic glutathione, and decreased liver damage (necrosis, steatosis, and inflammatory infiltrate). In contrast, treatment with 4-HC after the induction of chronic liver injury decreased IL-6 serum levels and liver damage (steatosis, inflammatory infiltrate, ballooning cells, steatofibrosis, and fibrosis degree). Thus, the 4-HC treatment is proposed as a preventive treatment against acute liver injury; moreover, these results suggested the potential of 4-HC as a curative treatment against chronic liver injury, but other scheme treatments must be evaluated in future.

Toward Understanding the Molecular Recognition of Fungal Chitin and Activation of the Plant Defense Mechanism in Horticultural Crops.

Large volumes of fruit and vegetable production are lost during postharvest handling due to attacks by necrotrophic fungi. One of the promising alternatives proposed for the control of postharvest diseases is the induction of natural defense responses, which can be activated by recognizing molecules present in pathogens, such as chitin. Chitin is one of the most important components of the fungal cell wall and is recognized through plant membrane receptors. These receptors belong to the receptor-like kinase (RLK) family, which possesses a transmembrane domain and/or receptor-like protein (RLP) that requires binding to another RLK receptor to recognize chitin. In addition, these receptors have extracellular LysM motifs that participate in the perception of chitin oligosaccharides. These receptors have been widely studied in Arabidopsis thaliana (A. thaliana) and Oryza sativa (O. sativa); however, it is not clear how the molecular recognition and plant defense mechanisms of chitin oligosaccharides occur in other plant species or fruits. This review includes recent findings on the molecular recognition of chitin oligosaccharides and how they activate defense mechanisms in plants. In addition, we highlight some of the current advances in chitin perception in horticultural crops.

Draft genome sequence of uropathogenic Escherichia coli U13824, a multidrug-resistant (MDR) and extended-spectrum-ß-lactamase (ESBL)-producing UPEC strain isolated from an adult woman with urinary tract infection.

Urinary tract infections (UTIs) caused by multidrug-resistant and extended-spectrum ß-lactamase-producing uropathogenic Escherichia coli are a worldwide concern. We report the draft genome of E. coli U13824 isolated from a female outpatient with UTI. This genome's availability strengthens the genomic surveillance of antimicrobial resistance and the spreading of these strains.

Complete mitochondrial genome of Gnathostoma binucleatum.

This report describes the mitochondrial genome of the parasite Gnathostoma binucleatum (G. binucleatum), which was obtained from naturally infected freshwater fish in Sinaloa, Mexico (22°46'00.1″N 105°40'21.8″W). G. binucleatum is responsible for human gnathostomiasis and is endemic to Mexico. It belongs to the Spirurida order of the Secernentea class of Nematoda.

Characterization of a Pathogenic Escherichia coli Strain Derived from Oreochromis spp. Farms Using Whole-Genome Sequencing.

Aquaculture is one of the fastest-growing food-producing sectors worldwide and tilapia (Oreochromis spp.) farming constitutes the major freshwater fish variety cultured. Because aquaculture practices are susceptible to microbial contamination derived from anthropogenic sources, extensive antibiotic usage is needed, leading to aquaculture systems becoming an important source of antibiotic-resistant and pathogenic bacteria of clinical relevance such as Escherichia coli (E. coli). Here, the antimicrobial resistance, virulence, and mobilome features of a pathogenic E. coli strain, recovered from inland farmed Oreochromis spp., were elucidated through whole-genome sequencing (WGS) and in silico analysis. Antimicrobial susceptibility testing (AST) and WGS were performed. Furthermore, phylogenetic group, serotype, multilocus sequence typing (MLST), acquired antimicrobial resistance, virulence, plasmid, and prophage content were determined using diverse available web tools. The E. coli isolate only exhibited intermediate susceptibility to ampicillin and was characterized as ONT:H21-B1-ST40 strain by WGS-based typing. Although only a single antimicrobial resistance-related gene was detected [mdf(A)], several virulence-associated genes (VAGs) from the atypical enteropathogenic E. coli (aEPEC) pathotype were identified. Additionally, the cargo of plasmid replicons from large plasmid groups and 18 prophage-associated regions were detected. In conclusion, the WGS characterization of an aEPEC isolate, recovered from a fish farm in Sinaloa, Mexico, allows insights into its pathogenic potential and the possible human health risk of consuming raw aquacultural products. It is necessary to exploit next-generation sequencing (NGS) techniques for studying environmental microorganisms and to adopt a one health framework to learn how health issues originate.

Genomic Profiling of Antibiotic-Resistant Escherichia coli Isolates from Surface Water of Agricultural Drainage in North-Western Mexico: Detection of the International High-Risk Lineages ST410 and ST617.

Aquatic environments are recognized as one of the main reservoirs for the emergence and dissemination of high-risk lineages of multidrug-resistant (MDR) bacteria of public health concern. However, the genomic characteristics of antibiotic-resistant Escherichia coli isolates from aquatic origins remain limited. Herein, we examined the antibiotic resistance and virulence genomic profiles of three E. coli recovered from surface water in northwest Mexico. Antimicrobial susceptibility testing, whole-genome sequencing (WGS), and in-depth in silico analysis were performed. Two E. coli exhibited MDR phenotypes. WGS-based typing revealed genetic diversity, and phylogenetic analysis corroborated a notable divergent relationship among the studied E. coli. One E. coli strain, harboring enterotoxigenic and extraintestinal pathogenic-associated virulence genes, was assigned to the ST4 lineage. MDR E. coli, belonging to the international high-risk clones ST410 and ST617, carried genes and mutations conferring resistance to aminoglycosides, ß-lactams, quinolones, sulfonamides, tetracyclines, and trimethoprim. This study describes, for the first time, the detection and genomic profiling of high-risk lineages of E. coli ST410 and ST617 from surface water in Mexico. Additionally, our results underscore the role of surface water as a reservoir for critical pathogenic and MDR E. coli clones and the need for the surveillance and monitoring of aquatic environments via WGS from the One Health perspective.

Association of phylogenetic distribution and presence of integrons with multidrug resistance in Escherichia coli clinical isolates from children with diarrhoea.

BACKGROUND: Escherichia coli strains include both commensal and virulent clones distributed in different phylogenetic groups. Antimicrobial resistance is an increasingly serious public health threat at the global level and integrons are important mobile genetic elements involved in resistance dissemination. This paper aims to determine the phylogenetic groups and presence of class 1 (intl1) and 2 (intl2) integrons in E. coli clinical isolates from children with diarrhoea, and to associate these characteristics with their antimicrobial resistance. METHODS: Phylogeny and presence of integrons (intl1 and intl2) were analysed by PCR and amplicon sequencing in 70 E. coli isolates from children with and without diarrhoea (35 of each group) from Sinaloa, Mexico; these variables were analysed for correlation with the antimicrobial resistance profile of the isolates. RESULTS: The most frequent phylogroups were A (42.9%) and B2 (15.7%). The E. coli isolates from children with diarrhoea were distributed in all phylogroups; while strains from children without diarrhoea were absent from phylogroups C, E, and clade I. The 17.1% of the isolates carried integrons (15.7% intI1 and 1.4% intI2); 28.6% of the isolates from children with diarrhoea showed the class 1 integron. Strains of phylogroup A showed the highest frequency of integrons (33.3%). The association of multidrug resistance and the presence of integrons was identified in 58.3% of strains isolated from children with diarrhoea included in phylogroups A and B2. The sequence analysis of intl1 and intl2 showed silent point mutations and similarities with plasmids of some APEC and AIEC strains. CONCLUSION: Commensal E. coli strains are potential disseminators of antimicrobial resistance, and the improvement in the use of antimicrobials to treat childhood diarrhoea is essential for the control of such resistance.

Draft genome sequence of Escherichia coli M51-3: a multidrug-resistant strain assigned as ST131-H30 recovered from infant diarrheal infection in Mexico.

OBJECTIVES: In this study, we report the draft genome sequence of a multidrug-resistant (MDR)Escherichia coli strain recovered from stool sample of an outpatient infant girl with acute diarrheal infection in Mexico. METHODS: Antimicrobial susceptibility testing and PCR-based detection of diarrheagenic E. coli (DEC) were performed. In addition, genomic DNA from E. coli strain M51-3 was sequenced using Ion Torrent PGM platform with 200-bp chemistry and generated reads were de novo assembled using SPAdes v3.11. The draft genome was annotated and analyzed regarding multilocus sequence typing (MLST), serotyping, fimH typing, plasmid replicons, acquired antimicrobial resistance and virulence genes using web tools available at the Center for Genomic Epidemiology. RESULTS: A draft genome comprising 5 088 545 bp in length and 5308 protein-coding sequences was generated. In silico typification revealed that E. coli strain M51-3 belongs to ST131-O25:H4-H30 pandemic subclone. Several genes associated with resistance to ß-lactams [blaTEM-1B], aminoglycosides [aph(3'')-Ib, aadA5, aph(6)-Id and aac(3)-IId], sulfonamides [sul1 and sul2], trimethoprim [dfrA17], and tetracycline [tet(A)] were identified. Besides, point mutations in gyrA, parC, and parE genes were detected. Interestingly, the enterotoxin-coding virulence gene senB was evidenced. CONCLUSIONS: To our knowledge, this is the first draft genome of an E. coli ST131-O25:H4-H30 strain recovered from infant diarrheal stool sample in Mexico. The genome sequence of E. coli M51-3 presented here will be helpful to understand the genomic diversity of this highly virulent and MDR successfully pandemic bacterial pathogen.

Whole-genome sequencing of Staphylococcus aureus L401, a mecA-negative community-associated methicillin-resistant strain isolated from a healthy carrier.

OBJECTIVES: Methicillin-resistant Staphylococcus aureus (MRSA) is a human pathogen of great concern owing to its antimicrobial resistance and virulence properties. Here we report the first draft genome sequence of a mecA-negative community-associated MRSA strain isolated from a healthy young Mexican paediatric carrier in order to reveal the genomic structure underlying the multidrug-resistant phenotype and to discover the virulence properties of this strain. METHODS: The draft genome sequence of S. aureus L401 was obtained using an Ion Torrent™ PGM platform. De novo assembled contigs were annotated, and antimicrobial resistance genes and virulence factors were identified using ResFinder and VirulenceFinder, respectively. In addition, a mutational survey of native pbp, gdpP and yjbH genes was performed. In silico multilocus sequence typing (MLST) and spa typing were also performed. RESULTS: S. aureus L401 has a genome size of 2 831 587 bp with 2799 protein-coding sequences. Various antimicrobial resistance genes conferring resistance to aminoglycosides, ß-lactams, fluoroquinolones and macrolide-lincosamide-streptogramin B antimicrobials were found. Although both mecA and staphylococcal cassette chromosome mec (SCCmec) elements were absent, a missense mutation in PBP3 was identified. Moreover, genes encoding exfoliative toxin A, γ- and ß-haemolysin, and several enterotoxins were also identified. S. aureus L401 belongs to ST109 and spa type t209. CONCLUSION: The availability of this genome will allow an insight into S. aureus resistance and virulence determinants as well as its epidemiology, lineage, evolution and genomic features involved in the paediatric commensal carriage.

Draft Genome Sequence of Escherichia coli Strain M15-4, a Typical Enteropathogenic E. coli Strain Isolated in Mexico.

We present here the first draft genome sequence of a typical enteropathogenic Escherichia coli serotype O55:H51 strain, M15-4, isolated from a 2-month-old infant girl with acute diarrhea. The study of this Mexican isolate will provide insights to the virulence and drug resistance traits involved in its pathogenic potential.

Draft Genome Sequence of a Mexican Community-Associated Methicillin-Resistant Staphylococcus epidermidis Strain.

We report here the first draft genome sequence of a Mexican communitarian methicillin-resistant Staphylococcus epidermidis (MRSE) strain whose genome harbors a wide variety of resistance determinants. The availability of this genome will allow the study of antibiotic resistance in Mexican staphylococci from a genomic perspective.

High prevalence of multidrug-resistant Escherichia coli isolates from children with and without diarrhoea and their susceptibility to the antibacterial activity of extracts/fractions of fruits native to Mexico.

PURPOSE: This paper aims to evaluate the antimicrobial resistance of Esherichia coli isolates from children under 5 years old, with and without diarrhoea, who were hospital outpatients in Culiacan, Sinaloa, Mexico. It also looks at the antimicrobial activity of fruit extracts against selected multidrug-resistant (MDR) E. coli strains. METHODOLOGY: A total of 205 E. coli isolates from stool samples were collected from 94 children under 5 years old who were outpatients from two hospitals in the city of Culiacan, Sinaloa, Mexico, during the autumn/winter of 2003/04; their resistance profiles to 19 commercial antimicrobials were investigated using the Kirby-Bauer method. The antibacterial activities of extracts/fractions of fruits (i.e. uvalama, Vitex mollis; ayale, Crescentia alata; and arrayan, Psidium sartorianum) were evaluated using the broth microdilution method. RESULTS: All E. coli isolates were susceptible to amikacin, nitrofurantoin and meropenem, and approximately 96 % were resistant to at least one antimicrobial, especially carbenicillin (93.2 %), cefuroxime sodium (53.7 %), ampicillin (40 %) and trimethoprim/sulfamethoxazole (35.1 %). Likewise, the frequency of MDR strains (44.9 %) was high, and no significant association with diarrhoea symptoms was found. Remarkably, all fruit extracts/fractions showed antibacterial activity against some, but not all, MDR isolates. The lowest minimal inhibitory concentration values were for the hexane fraction of arrayan (0.25 mg ml-1). CONCLUSION: A high number of antimicrobial-resistant E. coli (especially to ß-lactams and sulfonamides) and MDR isolates were detected in children under 5 years old, irrespective of diarrhoea symptoms; this is novel information for Culiacan, Sinaloa, Mexico. Moreover, our results showed that the studied fruit extracts/fractions are potential alternative or complementary treatments for MDR E. coli strains.

Giardia duodenalis genotypes among schoolchildren and their families and pets in urban and rural areas of Sinaloa, Mexico.

INTRODUCTION: Giardiasis is a human health concern worldwide, especially among schoolchildren. Giardia duodenalis genotypes A and B are infective to humans, but their zoonotic potential remains controversial. In Mexico, the most prevalent genotype is A, but B was also detected in southeastern Mexico. In Sinaloa state, northwestern Mexico, giardiasis is highly prevalent, but Giardia genotypes have been poorly studied. METHODOLOGY: This study aimed to investigate the distribution and clinical-epidemiological correlation of G. duodenalis genotypes in schoolchildren and their families and pets in urban and rural areas of Sinaloa state, Mexico. RESULTS: Among 395 schoolchildren (274 urban, 121 rural), 76 (49 urban, 27 rural) were infected with G. duodenalis. In total, 22 families (15 urban, 7 rural) of infected schoolchildren, consisting of 60 family members (41 urban, 19 rural) and 21 pet dogs (15 urban, 6 rural) were examined; 10 family members (5 urban, 5 rural) and 5 pet dogs (3 urban, 2 rural) of 10 families (6 urban, 4 rural) were infected. After PCR-RFLP analyses of vsp417 and gdh genes, genotype prevalence among infected urban schoolchildren was 79.5% AI, 12.8% AII, and 7.7% mixed AI+B. However, only AI genotype was found in family members and pets. In the rural area, only the AI genotype was detected. Genotypes were not correlated with clinical manifestations. CONCLUSIONS: This paper shows the presence of B genotype in northwestern Mexico for the first time. Detection of AI genotype in dogs suggested the possible role of dogs as the reservoir for human giardiasis in Sinaloa, Mexico.

Differentially expressed cDNAs in Alternaria alternata treated with 2-propenyl isothiocyanate.

The molecular mechanism of the fungal tolerance phenotype to fungicides is not completely understood. This knowledge would allow for the development of environmentally friendly strategies for the control of fungal infection. With the goal of determining genes induced by 2p-ITC, a forward suppressive subtractive hybridization was performed using cDNAs from ITC-treated Alternaria alternata as a "tester" and from untreated fungus as a "driver." Using this approach, a library containing 102 ESTs was generated that resulted in 50 sequences after sequence assembly (17 contigs and 33 singletons). Blastx analysis revealed that 38% and 40% of the sequences showed significant similarity with known and hypothetical proteins, respectively, whereas 18% were not similar to known genes. These last sequences could represent novel genes that play an unknown role in the molecular responses of fungi during adaptation to 2p-ITC. Clones similar to opsins, ABC transporters, calmodulin, ATPases and SNOG proteins were identified. Using real-time RT-PCR analysis, significant inductions of an ABC transporter and a Ca(++) ATPase during 2p-ITC treatment were discovered. These results suggest that the fungal resistance phenotype to 2p-ITC involves calcium ions and 2p-ITC efflux via an ABC transporter.

Analysis of a suppressive subtractive hybridization library of Alternaria alternata resistant to 2-propenyl isothiocyanate

Background Isothiocyanates (ITCs) are natural products obtained from plants of the Brassicas family. They represent an environmentally friendly alternative for the control of phytopathogenic fungi. However, as it has been observed with synthetic fungicides, the possibility of inducing ITC-resistant strains is a major concern. It is, therefore, essential to understanding the molecular mechanisms of fungal resistance to ITCs. We analyzed a subtractive library containing 180 clones of an Alternaria alternata strain resistant to 2-propenyl ITC (2-pITC). After their sequencing, 141 expressed sequence tags (ESTs) were identified using the BlastX algorithm. The sequence assembly was carried out using CAP3 software; the functional annotation and metabolic pathways identification were performed using the Blast2GO program. Results The bioinformatics analysis revealed 124 reads with similarities to proteins involved in transcriptional control, defense and stress pathways, cell wall integrity maintenance, detoxification, organization and cytoskeleton destabilization; exocytosis, transport, DNA damage control, ribosome maintenance, and RNA processing. In addition, transcripts corresponding to enzymes as oxidoreductases, transferases, hydrolases, lyases, and ligases, were detected. Degradation pathways for styrene, aminobenzoate, and toluene were induced, as well as the biosynthesis of phenylpropanoid and several types of N-glycan. Conclusions The fungal response showed that natural compounds could induce tolerance/resistance mechanisms in organisms in the same manner as synthetic chemical products. The response of A. alternata to the toxicity of 2-pITC is a sophisticated phenomenon including the induction of signaling cascades targeting a broad set of cellular processes. Whole-transcriptome approaches are needed to elucidate completely the fungal response to 2-pITC.