title: Dynamics of antibiotic resistance genes and presence of putative pathogens during ambient temperature anaerobic digestion.
abstract: OBJECTIVE
  This study was focused on evaluating the persistency of antimicrobial resistance (AR) genes and putative pathogenic bacteria in an anaerobic digesters operating at mesophilic ambient temperature, in two different year seasons: summer and winter.
  
  
  RESULTS
  Abundance and dynamic of AR genes encoding resistance to macrolides (ermB), aminoglycosides (aphA2) and beta-lactams (blaTEM -1 ) and persistency of potentially pathogenic bacteria in pilot-scale anaerobic digesters were investigated. AR genes were determined in the influent and effluent in both conditions. Overall, after 60 days, reduction was observed for all evaluated genes. However, during the summer, anaerobic digestion was more related to the gene reduction as compared to winter. Persistency of potentially pathogenic bacteria was also evaluated by metagenomic analyses compared to an in-house created database. Clostridium, Acinetobacter and Stenotrophomonas were the most identified.
  
  
  CONCLUSIONS
  Overall, considering the mesophilic ambient temperature during anaerobic digestion (summer and winter), a decrease in pathogenic bacteria detection through metagenomic analysis and AR genes is reported. Although the mesophilic anaerobic digestion has been efficient, the results may suggest medically important bacteria and AR genes persistency during the process.
  
  
  CONCLUSIONS
  This is the first report to show AR gene dynamics and persistency of potentially pathogenic bacteria through metagenomic approach in cattle manure ambient temperature anaerobic digestion.
authors.affiliation: Department of Parasitology, Microbiology and Immunology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil; INRA-Institute National Recherche Agronomique, Laboratoire de Biotechnologie de l'Environnement, Narbonne, France.
authors.forename: J A
authors.initials: JA
authors.lastname: Resende
authors.forename: C G
authors.initials: CG
authors.lastname: Diniz
authors.forename: V L
authors.initials: VL
authors.lastname: Silva
authors.forename: M H
authors.initials: MH
authors.lastname: Otenio
authors.forename: A
authors.initials: A
authors.lastname: Bonnafous
authors.forename: P B
authors.initials: PB
authors.lastname: Arcuri
authors.forename: J-J
authors.initials: JJ
authors.lastname: Godon
mesh_terms: D000617:Aminoglycosides; D000693:Anaerobiosis; D000818:Animals; D000900:Anti-Bacterial Agents; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification; D019149:Bioreactors; D002417:Cattle; D004352:Drug Resistance, Microbial / Q000235:genetics*; D018628:Gene Dosage; D018942:Macrolides; D008372:Manure / Q000382:microbiology; D056186:Metagenomics; D012621:Seasons; D013696:Temperature; D047090:beta-Lactams
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D018942:Macrolides; D008372:Manure; D047090:beta-Lactams
keywords: antibiotics resistance gene abundance; bacterial pathogens; biofertilizer dairy cattle manure; biogas; seasonal variations