deletions | additions       diff --git a/AbstractImportanceIntroductionHistorically_b_lactam_antibiotics_are__.html b/AbstractImportanceIntroductionHistorically_b_lactam_antibiotics_are__.html  index d063ecc..2e34336 100644  --- a/AbstractImportanceIntroductionHistorically_b_lactam_antibiotics_are__.html  +++ b/AbstractImportanceIntroductionHistorically_b_lactam_antibiotics_are__.html 
...
author = {Chris S. Smillie and Mark B. Smith and Jonathan Friedman and Otto X. Cordero and Lawrence A. David and Eric J. Alm},  title = {Ecology drives a global network of gene exchange connecting the human microbiome},  journal = {Nature}  }" data-bib-key="Smillie_2011" contenteditable="false">Smillie 2011), which reported an specificity of ARGs with analyzed environments, with a high degree of intra-habitat mobility of ARGs and few probabilities of genetic ARG transfer between different environmnets. In environments. In  this context, different factors such as MGEs (specially inb-lactamase  flanking regions), founder effect, ecological connectivity, fitness cost or second-order selection may limit the gene transfer of ARGs between environments ( ...
author = {Jos{\'{e}} L. Mart{\'{\i}}nez},  title = {Bottlenecks in the Transferability of Antibiotic Resistance from Natural Ecosystems to Human Bacterial Pathogens},  journal = {Front. Microbio.}  }" data-bib-key="Mart_nez_2012" contenteditable="false">Mart' 2012, Forsberg 2014, Udikovic-Kolic 2014).

This 

In order to analyze the grade of similarity between the b-lactamases detected in this study and the b-lactamases of clinical origin, present in the EX-B database, we choose four clinical important b-lactamases such blaTEM, blaCTX-M, blaGES (class A b-lactamases) and blaOXA (class D), 

This  study is an attempt to screen the presence of b-lactamases on non-clinical environments based on public shotgun metagenome studies. The methodology here presented, try to reduce the differences produced by the comparison of several sequencing studies; however, in the in the  whole, our results shed light for first time on the wide distribution and content of b-lactamases on different environments, including non-clinical and non anthropogenically impacted environments. Despite the wide b-lactamase distribution, b-lactamases exhibit certain environmental fingerprint; in addition, some b-lactamase genes exhibit a higher presence in some specific environments, which strengthening this environmental b-lactamase fingerprint. Finally, our network analysis suggest that b-lactamases can move from a given environment to other, but this type of events are rare in the time.  

Materials  

Materials  and methods

Data set

Shotgun metagenomic sequences obtained by Illumina sequencing process were used in this study and downloaded from two repositories, MG-RAST (http://metagenomics.anl.gov/) and EBI METAGENOMICS (https://www.ebi.ac.uk/metagenomics/). A total of 232 metagenomes related to X different projects (Table S1) embedding 4.7 billion sequences, were retrieved after quality control steps performed by each repositorie. Each metagenome was associated with different sampling habitats including soil (undisturbed and agricultural soils), fresh water, ocean, glaciers, human gut, animal gut (rumen and feces), and effluents from wastewater treatment plants.

Construction of a comprehensive β-lactamases database 

Characterization of metagenome sequences associated to β-lactamase genes was preceded by construction of an  extensive β-lactamase database (EX-B) that integrated four clinically-important  publically-available databases: The Lahey β-lactamase database,