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Sampling the antibiotic resistome

Antimicrobial Research Centre, Department of Biochemistry and Biomedical Sciences, McMaster University, Ontario, Canada, L8N 3Z5.
Science (Impact Factor: 31.48). 02/2006; 311(5759):374-7. DOI: 10.1126/science.1120800
Source: PubMed

ABSTRACT Microbial resistance to antibiotics currently spans all known classes of natural and synthetic compounds. It has not only hindered our treatment of infections but also dramatically reshaped drug discovery, yet its origins have not been systematically studied. Soil-dwelling bacteria produce and encounter a myriad of antibiotics, evolving corresponding sensing and evading strategies. They are a reservoir of resistance determinants that can be mobilized into the microbial community. Study of this reservoir could provide an early warning system for future clinically relevant antibiotic resistance mechanisms.

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    • "It is not yet clear and arguments among scientists increase daily about the involvement of man and his many anthropogenic activities in the spread of resistance elements in microorganisms . Several studies have reported lack of tangible relationship between anthropogenic activities and antibiotic resistance in bacteria and many believe that the elements that selects for resistance are naturally present within microbial genome (Davis and Anandan, 1970; Hughes and Datta, 1983; Barlow and Hall, 2002; Hall and Barlow, 2004; D'Costa et al., 2006, 2011; Wright, 2007, 2010; Baltz, 2008; Brown and Balkwill, 2009; Thaller et al., 2010; Toth et al., 2010; Bhullar et al., 2012; Cox and Wright, 2013). On the other hand, evidence abound that increased bacterial resistance to antibiotics and the transfer of resistance elements is a modern phenomenon having a strong link with anthropogenic activities (Knapp et al., 2010; Bhullar et al., 2012). "
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    ABSTRACT: Antibiotics are emerging environmental contaminants, causing both short-term and long-term alterations of natural microbial communities due to their high biological activities. The antibiotic resistance pattern of bacteria from anthropogenic polluted Oluwa River, Nigeria was carried out. Microbial profiling and antibiotic sensitivity tests were carried out on water and sediment samples using 13 different antibiotics. Microorganisms isolated include those in the genera Bacillus, Micrococcus, Pseudomonas, Streptococcus, Proteus and Staphylococcus. The microbial count of isolates from water samples ranged between 94.10 × 102 Cfu/100 ml and 156.20 × 102 Cfu/100 ml while that of sediment samples ranged from 2.55 × 104 Cfu g−1 to 14.30 × 104 Cfu g−1. From the water isolates, 100% resistance to antibiotics was found in Micrococcus spp. and Pseudomonas spp. while another Micrococcus, Streptococcus, Staphylococcus and Bacillus spp. showed between 40% and 90% resistances. From the sediment isolates, 100% resistance to antibiotics was found in a Bacillus spp. and Pseudomonas spp. while another Bacillus, Micrococcus, Staphylococcus, Streptococcus and Proteus spp. showed between 70% and 90% resistances. Multiple antibiotic resistance (MAR) was shown by all the isolates and Bacillus, Micrococcus and Pseudomonas spp. showed the highest resistances (100%) to all antibiotics. Thus, Oluwa River is not safe for public consumption.
    10/2014; 40(3). DOI:10.1016/j.ejar.2014.09.002
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    • "The genus Aeromonas has been the subject of various antimicrobial susceptibility studies over the last 30 years (Overman and Janda 1999). Currently, microbial resistance to antibiotics spans some known classes of natural and synthetic drug agents (D'Costa et al. 2006). In the present study, we observed that all A. hydrophila isolates were resistant to ampicillin and sulfamonomethoxine, and the majority of the isolates were resistant to erythromycin and tylosin, whereas norfloxacin, ciprofl oxacin, enrofl oxacin and fl orfenicol were more effective. "
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    ABSTRACT: Aeromonas hydrophila isolates from clinical cases (n=43) were tested against 8 antimicrobial agents and typed by outer membrane protein (OMP) pattern by using sodium dodecyl sulfate gel electrophoresis. All isolates were resistant to ampicillin (MICs, ≥16 μg mL−1) and sulfamonomethoxine (MICs, ≥64 μg mL−1), but susceptible to norfloxacin (MICs, ≤0.5 μg mL−1). There was a high incidence of resistance to erythromycin (90.70%) and tylosin (93.02%), while a low incidences of resistance to ciprofloxacin (2.33%), enrofloxacin (2.33%) and florfenicol (4.65%). Six different outer membrane protein patterns were found among 34 isolates by analyzing proteins in the range of 22 to 50 kDa, other than 9 isolates with their respective profiles. The strains with the similar OMP profiles had similar resistances. Compared with the other strains from the same OMP patterns, NB-1, A.Pun and MR-1 had lacked the proteins in the range of 30 to 45 kDa and their resistance to florfenicol substantially increased. It is speculated that the outer membrane protein changes might correlate with decreased susceptibility to florfenicol in the three strains. Some strains which showed completely identical OMP types had a little difference in their resistance to fluoroquinolones, indicating that there might be other factors that were involved in the antimicrobial resistance of A. hydrophila.
    Journal of Integrative Agriculture 04/2014; 13(4):911–917. DOI:10.1016/S2095-3119(13)60312-3 · 0.63 Impact Factor
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    • "In this context, efforts to find such molecules should be intensified. Since environmental organisms are the source of most resistance genes and antibiotics (D'Costa et al., 2006), screens of bacterial natural products are likely to be productive in finding molecules that inhibit antibiotic resistance elements, as proven by the discovery of clavulanic acid (Brown et al., 1976). Additionally, a screen of a library of plant-derived 2 P. Bernal, C. Molina-Santiago, A. Daddaoua and M. A. Llamas "
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Vanessa D'Costa