Escherichia coli and the antimicrobial pressure exerted on this microorganism can be modulated by factors dependent on the host. In this paper, we describe the distribution of antimicrobial resistance to amikacin, tobramycin, ampicillin, amoxicillin clavulanate, cefuroxime, cefoxitin, cefotaxime, imipenem, ciprofloxacin, fosfomycin, nitrofurantoin, and trimetoprim-sulfametoxazole in more than 100,000 E. coli isolates according to culture site and patient age, gender, and location. Bayesian inference was planned in all statistical analysis, and Markov chain Monte Carlo simulation was employed to estimate the model parameters. Our findings show the existence of a marked difference in the susceptibility to several antimicrobial agents depending on from where E. coli was isolated, with higher levels of resistance in isolates from medical devices, the respiratory system, and the skin and soft tissues; a higher resistance percentage in men than in women; and the existence of a clear difference in antimicrobial resistance with an age influence that cannot be explained merely by means of an increase of resistance after exposure to antimicrobials. Both men and women show increases in resistance with age, but while women show constant levels of resistance or slight increases during childbearing age and greater increases in the premenopausal age, men show a marked increase in resistance in the pubertal age. In conclusion, an overwhelming amount of data reveals the great adaptation capacity of E. coli and its close interaction with the host. Sex, age, and the origin of infection are determining factors with the ability to modulate antimicrobial resistances.

Contamination of surface waters in developing countries is a great concern. Treated and untreated wastewaters have been discharged into rivers and streams, leading to possible waterborne infection outbreaks and may represent a significant dissemination mechanism of antibiotic resistance genes. In this study, the water quality of San Pedro River, the main river and pluvial collector of the Aguascalientes State, Mexico was assessed. Thirty sample locations were tested throughout the River. The main physicochemical parameters of water were evaluated. Results showed high levels of fecal pollution as well as inorganic and organic matter abundant enough to support the heterotrophic growth of microorganisms. These results indicate poor water quality in samples from different locations. One hundred and fifty Escherichia coli were collected and screened by PCR for several virulence genes. Isolates were classified as either pathogenic (n = 91) or commensal (n = 59). The disc diffusion method was used to determine antimicrobial susceptibility to 13 antibiotics. Fifty-two percent of the isolates were resistant to at least one antimicrobial agent and 30.6% were multi-resistant. Eighteen E. coli strains were quinolone resistant of which 16 were multi-resistant. Plasmid-mediated quinolone resistance (PMQR) genes were detected in 12 isolates. Mutations at the Ser-83→Leu and/or Asp-87→Asn in the gyrA gene were detected as well as mutations at the Ser-80→Ile in parC. An E. coli microarray (Maxivirulence V 3.1) was used to characterize the virulence and antimicrobial resistance genes profiles of the fluoroquinolone-resistant isolates. Antimicrobial resistance genes such as blaTEM, sulI, sulII, dhfrIX, aph3 (strA), and tet (B) as well as integrons were found in fluoroquinolone (FQ) resistance E. coli strains. The presence of potential pathogenic E. coli and antibiotic resistance in San Pedro River such as FQ resistant E. coli could pose a potential threat to human and animal health.

Background End-stage renal failure of unknown origin (ESRD-UO) is a public health problem in Mexico and many regions of the world. The prevalence of ESRD-UO in Aguascalientes Mexico is one of the highest worldwide, particularly in adults between 20 and 40 years of age. Aim To screen adolescents for chronic kidney disease (CKD), identify risk factors, and histologically characterize adolescents with persistent albuminuria (pACR). Methodology This is a cross-sectional, observational, and comparative study of adolescents in whom serum creatinine and the albumin creatinine ratio (ACR) were determined when screening for CKD. A clinical evaluation and risk factor survey were conducted. Patients with an abnormal ACR (≥ 30 mg/gr) or a low glomerular filtration rate (GFR) (≤75 ml/min/1.73 m2) were reevaluated and a renal ultrasound was obtained (rUS). A kidney biopsy was performed in patients with pACR. Results Five-hundred and thirteen (513) students were included, 19 had pACR and 494 were controls. The prevalence of pACR was 3.7% (95%CI 2.1 – 5.3). Only one patient had a decreased GRF. None of the patients with pACR had anatomical abnormalities of the urinary tract by rUS. Patients with pACR had a decreased total renal volume in comparison with the control group (150 vs 195 ml/m2, p <0.01). Eighteen (18) kidney biopsies were performed, 72% had glomerulomegaly, and only one patient had mild fibrosis. Podocyte abnormalities were evident on electron microscopy: partial fusion (100%), microvillous degeneration (80%), and increased organelles (60%). Risk factors for pACR were: homestead proximity to maize crops, the use of pesticides at the father´s workplace, a family history of CKD, and blood pressure abnormalities. The body mass index and breastfeeding were protective factors. Conclusions The prevalence of pACR in adolescents in Aguascalientes is high, and histologic compromise is characterized by podocyte injury in the absence of fibrosis. The renal volume of pACR patients was decreased, suggesting oligonephronia. Exposure to environmental toxins such as pesticides, even prenatally, may be responsible for this pathological entity. Screening programs in adolescents by determining ACR are necessary in our milieu.

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A total of sixteen composite soil and sediment samples were collected during the rainy and dry season in Asientos, Aguascalientes, Mexico, an area recently affected by increased mining operations. Physicochemical characterization showed that substrates were moderately to strongly calcareous with predominantly neutral to slightly alkaline pH, moderate to high cation-exchange capacity and high organic matter content. Due to these conditions, Cd, Pb, Cu and Zn were not water leachable despite high concentrations; up to 105.3, 7052.8, 414.7 and 12,263.2 mg kg(-1) respectively. However, Cd and Pb were considered to be easily mobilizable as they were found predominantly associated with exchangeable and carbonate fractions, whereas Cu and Zn were found associated with Fe/Mn oxide and organic matter fractions. The results highlighted the influence of physicochemical substrate properties on the mobility of metals and its importance during the evaluation of the potential current and future risk metal contamination presents in affected areas.