Glutathione-related genetic polymorphisms are associated with mercury retention and nephrotoxicity in gold-mining settings of a Colombian population.

Mercury (Hg) vapor can produce kidney injury, where the proximal tubule region of the nephron is the main target of the Hg-induced oxidative stress. Hg is eliminated from the body as a glutathione conjugate. Thus, single nucleotide polymorphisms (SNPs) in glutathione-related genes might modulate the negative impact of this metal on the kidneys. Glutathione-related SNPs were tested for association with levels of Hg and renal function biomarkers between occupationally exposed (n = 160) and non-exposed subjects (n = 121). SNPs were genotyped by TaqMan assays in genomic DNA samples. Total mercury concentration was measured in blood, urine and hair samples. Regression analyses were performed to estimate the effects of SNPs on quantitative traits. Alleles GCLM rs41303970-T and GSTP1 rs4147581-C were significantly overrepresented in the exposed compared with the non-exposed group (P < 0.01). We found significant associations for GCLM rs41303970-T with higher urinary clearance rate of Hg (ß = 0.062, P = 0.047), whereas GCLC rs1555903-C was associated with lower levels of estimated glomerular filtration rate in the non-exposed group (eGFR, ß = - 3.22, P = 0.008) and beta-2-microglobulin in the exposed group (ß-2MCG, ß = - 19.32, P = 0.02). A SNP-SNP interaction analysis showed significant epistasis between GSTA1 rs3957356-C and GSS rs3761144-G with higher urinary levels of Hg in the exposed (ß = 0.13, P = 0.04) but not in the non-exposed group. Our results suggest that SNPs in glutathione-related genes could modulate the pathogenesis of Hg nephrotoxicity in our study population by modulating glutathione concentrations in individuals occupationally exposed to this heavy metal.

Genetic Polymorphisms in Multispecific Transporters Mitigate Mercury Nephrotoxicity in an Artisanal and Small-Scale Gold Mining Community in Colombia.

In artisanal and small-scale gold mining, occupational exposure to mercury (Hg) vapor is related to harmful effects on several organs, including the kidneys. We previously reported significantly increased levels of Hg in blood and urine despite normal kidney function in individuals from Colombia occupationally exposed to Hg compared with those nonexposed. We evaluated the contribution of 4 genetic variants in key genes encoding the transporters solute carrier (SLC; rs4149170 and rs4149182) and ATP-binding cassette(ABC; rs1202169 and rs1885301) in the pathogenesis of nephrotoxicity due to Hg exposure in these groups. Regression analysis was performed to determine the association between the blood- and urine-Hg concentration with SLC and ABC polymorphisms in 281 Colombian individuals (160 exposed and 121 nonexposed to Hg). We found an enrichment of ABCB1 rs1202169-T allele in the exposed group (p = .011; OR= 2.05; 95% CI = 1.18-3.58) compared with the nonexposure group. We also found that carriers of SLC22A8 rs4149182-G and ABCB1 rs1202169-T alleles had a higher urinary clearance rate of Hg than noncarriers (ß = 0.13, p = .04), whereas carriers of SLC22A6 rs4149170-A and ABCB1 rs1202169-C alleles showed abnormal levels of estimated glomerular filtration rate (ß = -84.96, p = .040) and beta-2-microglobulin (ß = 743.38, p < .001). Our results suggest that ABCB1 rs1202169 and its interaction with SLC22A8 rs4149182 and SLC22A6 rs4149170 could mitigate Hg nephrotoxicity by controlling the renal proximal tubule cell accumulation of inorganic Hg. This will be useful to estimate the risk of kidney toxicity associated to Hg and the genetic selection to aid adaptation to Hg-rich environments.

First isolate of KPC-2-producing Klebsiella pneumonaie sequence type 23 from the Americas.

KPC-2-producing Klebsiella pneumoniae isolates mainly correspond to clonal complex 258 (CC258); however, we describe KPC-2-producing K. pneumoniae isolates belonging to invasive sequence type 23 (ST23). KPC-2 has scarcely been reported to occur in ST23, and this report describes the first isolation of this pathogen in the Americas. Acquisition of resistant markers in virulent clones could mark an evolutionary step toward the establishment of these clones as major nosocomial pathogens.

Portadores nasales de Staphylococcus aureus en personal que labora en un Hospital de Santander / Nasal carriers of Staphylococcus aureus in the personnel that works in a Hospital of Santander

Introducción: Las infecciones intrahospitalarias constituyen un problema de salud pública mundial, la diseminación de bacterias patógenas a partir del personal de salud, ha sido el enfoque de numerosas investigaciones que buscan mejorar la calidad de vida de los pacientes. Objetivo: Determinar la frecuencia de portadores de Staphylococcus aureus en fosas nasales del personal que labora en las unidades de cuidados intensivos, infectología pediátrica y lactario en un Hospital en Santander. Metodología: Se estudiaron muestras provenientes de fosas nasales de 87 trabajadores del Hospital. Las cepas aisladas se identificaron mediante las pruebas bioquímicas y posteriormente, se determinó el perfil de susceptibilidad ante diferentes antibióticos, se realizó test D a las cepas de S. aureus. Resultados: La frecuencia de portadores de bacterias patógenas fue 41,4%; el patógeno aislado con mayor frecuencia fue S. aureus (72%), donde el porcentaje de S. aureus meticilino-resistentes (SARM) fue de 11,6%, Enterobacter aerogenes (6%), Proteus mirabilis (2,3%), Haemophylus influenzae (1,1%), Citrobacter koseri (1,1%) y Providencia rettgeri (1,1%). Conclusión: S. aureus es el agente aislado con mayor frecuencia de las fosas nasales del personal de salud y la presencia de SARM es preocupante por su resistencia a los antibióticos, lo que dificulta su tratamiento. Este hecho evidencia la necesidad de actuar con un carácter preventivo, en el cual el control de portadores es crítico y debe asociarse con medidas de bioseguridad que establezcan barreras más eficientes, para reducir la diseminación del microorganismo y la ocurrencia de infecciones intrahospitalarias. Salud UIS 2011; 43 (2): 111-117.

Introduction: Nosocomial infections are a public health problem worldwide, its spread start from health personnel carrier of pathogenic bacteria, it has been the focus of a large number of research to improve the quality of life of the patients. Objective: To determine the frequency of nasal carriers of Staphylococcus aureus in the personnel that works in intensive care units (adults ICU and pediatric ICU), pediatric infectology and lactary in a Hospital in Santander. Methodology: Nasal samples from 87 workers from of the Hospital were studied. Isolated strains were identified by the corresponding biochemical tests and subsequently determined their susceptibility profiles to different antibiotics and test D for S. aureus. Results: The frequency of nasal carriers of pathogenic bacteria was 41.4%; it was found that S. aureus was the most isolated pathogenic microorganism, with a frequency of (72%). The percentage of meticilin resistant S. aureus (MRSA) was 11.6% , Enterobacter aerogenes (6%), Proteus mirabilis (2.3%); Haemophylus influenzae (1.1%); Citrobacter koseri (1.1%) and Providencia rettgeri (1.1%). Conclusion: S. aureus is the most frequently isolated agent in health personnel's nasal nostrils and the presence of MRSA is worrying, additionally, it presents characteristic of resistance to antibiotics, making harder its treatment. This fact evidences the necessity to act with a preventive character, in which the control of carriers is critical and it should be associated with biosecurity measures to establish effective barriers to reduce the dissemination of the microorganism and occurrence of nosocomial infections. Salud UIS 2011; 43 (2): 111-117.