DYNAMICS OF ANTIMICROBIAL RESISTANCE BETWEEN THE HOSPITAL AND THE ENVIRONMENT

Funder

Organizational Unit

Publications

Bottled mineral water as a potential source of antibiotic resistant bacteria

Publication . Falcone-Dias, Maria Fernanda; Vaz-Moreira, Ivone; Manaia, Célia M.

The antibiotic resistance phenotypes of the cultivable bacteria present in nine batches of two Portuguese and one French brands of commercially available mineral waters were examined. Most of the 238 isolates recovered on R2A, Pseudomonas Isolation agar or on these culture media supplemented with amoxicillin or ciprofloxacin, were identified (based on 16S rRNA gene sequence analysis) as Proteobacteria of the divisions Beta, Gamma and Alpha. Bacteria resistant to more than three distinct classes of antibiotics were detected in all the batches of the three water brands in counts up to 102 CFU/ml. In the whole set of isolates, it was observed resistance against all the 22 antimicrobials tested (ATB, bio- Me´rieux and disc diffusion), with most of the bacteria showing resistance to three or more classes of antibiotics. Bacteria with the highest multi-resistance indices were members of the genera Variovorax, Bosea, Ralstonia, Curvibacter, Afipia and Pedobacter. Some of these bacteria are related with confirmed or suspected nosocomial agents. Presumable acquired resistance may be suggested by the observation of bacteria taxonomically related but isolated from different brands, exhibiting distinct antibiotic resistance profiles. Bottled mineral water was confirmed as a possible source of antibiotic resistant bacteria, with the potential to be transmitted to humans.

2012Journal article

Restricted access

The influence of the autochthonous wastewater microbiota and gene host on the fate of invasive antibiotic resistance genes

Publication . Narciso-da-Rocha, Carlos; Manaia, Célia M.

The aim of this study was to assess the fate of invasive antibiotic resistance genes (ARG) discharged in wastewater. With this objective, antibiotic resistant bacteria (ARB) known to harbor specific ARG were inoculated in wastewater (hospital effluent, or municipal raw and treated wastewater) and in ultra-pure sterile water microcosms. Two sets of wastewater ARB isolates were used - set 1, Enterococcus faecalis, Acinetobacter johnsonii, Klebsiella pneumoniae and set 2, Enterococcus faecium, Acinetobacter johnsonii, Escherichia coli. Non-inoculated controls were run in parallel. Samples were collected at the beginning and at the end (15 days) of the incubation period and the abundance of the genes 16S rRNA, intI1, blaTEM and vanA and the bacterial community composition were analyzed. In general, the genes blaTEM and vanA had lower persistence in wastewater and in ultra-pure water than the genes 16S rRNA or the class 1 integron integrase intI1. This effect was more pronounced in wastewater than in ultra-pure water, evidencing the importance of the autochthonous microbiota on the elimination of invasive ARG. Wastewater autochthonous bacterial groups most correlated with variations of the genes intI1, blaTEM and vanA were members of the classes Gammaproteobacteria, Bacilli or Bacteroidia. For blaTEM, but not for vanA, the species of the ARB host was important to determine its fate. These are novel findings on the ecology of ARB in wastewater environments.

2017Journal article

Restricted access

Assessment of copper and zinc salts as selectors of antibiotic resistance in Gram-negative bacteria

Publication . Becerra-Castro, Cristina; Machado, Rita A.; Vaz-Moreira, Ivone; Manaia, Célia M.

Some metals are nowadays considered environmental pollutants. Although some, like Cu and Zn, are essential for microorganisms, at high concentrations they can be toxic or exert selective pressures on bacteria. This study aimed to assess the potential of Cu or Zn as selectors of specific bacterial populations thriving in wastewater. Populations of Escherichia coli recovered on metal-free and metal-supplemented culture medium were compared based on antibiotic resistance phenotype and other traits. In addition, the bacterial groups enriched after successive transfers in metal-supplemented culture medium were identified. At a concentration of 1 mM, Zn produced a stronger inhibitory effect than Cu on the culturability of Enterobacteriaceae. It was suggested that Zn selected populations with increased resistance prevalence to sulfamethoxazole or ciprofloxacin. In non-selective culture media, Zn or Cu selected for mono-species populations of ubiquitous Betaproteobacteria and Flavobacteriia, such as Ralstonia pickettii or Elizabethkingia anophelis, yielding multidrug resistance profiles including resistance against carbapenems and third generation cephalosporins, confirming the potential of Cu or Zn as selectors of antibiotic resistant bacteria.

2015Journal article

Restricted access

Quinolone-resistant Escherichia coli isolated from birds of prey in Portugal are genetically distinct from those isolated from water environments and gulls in Portugal, Spain and Sweden

Publication . Vredenburg, Jana; Varela, Ana Rita; Hasan, Badrul; Bertilsson, Stefan; Olsen, Björn; Narciso-da-Rocha, Carlos; Bonnedahl, Jonas; Stedt, Johan; Costa, Paulo Martins Da; Manaia, Célia M.

The influence of geographic distribution and type of habitat on the molecular epidemiology of ciprofloxacin resistant Escherichia coli was investigated. Ciprofloxacin resistant E. coli from wastewater, urban water with faecal contamination and faeces of gulls, pigeons and birds of prey, from Portugal, Spain and Sweden were compared based on multilocus sequence typing (MLST) and quinolone resistance genetic determinants. Multi-locus sequence typing allowed the differentiation of E. coli lineages associated with birds of prey from those inhabiting gulls and waters. E. coli lineages of clinical relevance, such as the complex ST131, were detected in wastewater, streams and gulls in Portugal, Spain and Sweden. Quinolone resistance was due to gyrA and parC mutations, although distinct mutations were detected in birds of prey and in wastewater, streams and gulls isolates. These differences were correlated with specific MLST lineages, suggesting resistance inheritance. Among the plasmid-mediated quinolone resistance genes, only aac(6′)-ib-cr and qnrS were detected in wastewater, streams and gulls isolates, but not in birds of prey. The horizontal transfer of the gene aac(6′)-ib-cr could be inferred from its occurrence in different MLST lineages

2014Journal article

Restricted access

Molecular characterization of quinolone resistance mechanisms and extended-spectrum β-lactamase production in Escherichia coli isolated from dogs

Publication . Meireles, D.; Leite-Martins, L.; Bessa, L. J.; Cunha, S.; Fernandes, R.; Matos, A. de; Manaia, C. M.; Costa, P. Martins da

The increasing prevalence of antimicrobial resistances is now a worldwide problem. Investigating the mechanisms by which pets harboring resistant strains may receive and/or transfer resistance determinants is essential to better understanding how owners and pets can interact safely. Here, we characterized the genetic determinants conferring resistance to β-lactams and quinolones in 38 multidrug-resistant Escherichia coli isolated from fecal samples of dogs, through PCR and sequencing. The most frequent geno-type included the β-lactamase groups TEM (n = 5), and both TEM + CTX-M-1 (n = 5). Within the CTX-Mgroup, we identified the genes CTX-M-32, CTX-M-1, CTX-M-15, CTX-M-55/79, CTX-M-14 and CTX-M-2/44. Thirty isolates resistant to ciprofloxacin presented two mutations in the gyrA gene and one or two mutations in the par C gene. A mutation in gyr A (reported here for the first time), due to a transversion andtransition (TCG → GTG) originating a substitution of a serine by a valine in position 83 was also detected.The plasmid-encoded quinolone resistance gene, qnrs1, was detected in three isolates. Dogs can be a reservoir of genetic determinants conferring antimicrobial resistance and thus may play an important role in the spread of antimicrobial resistance to humans and other co-habitant animals.

2015Journal article

Restricted access