Article

Plasmid mediated antibiotic resistance in marine bacteria

CAS in Marine Biology, Annamalai University, Parangipettai-608 502, India.
Journal of Environmental Biology (Impact Factor: 0.56). 08/2007; 28(3):617-21.
Source: PubMed

ABSTRACT

This research work was conducted in Uppanar estuary to ascertain the role of plasmids in the antibiotic resistance of bacteria. Water and sediment samples were collected for a period of three months. When tested against 20 antibiotics 22 MAR strains were isolated from the samples, which were found resistant to 5-13 antibiotics. They belong to 7 genera and 10 species. Gram-negative bacteria namely Neisseria mucosa, N. sicca, Branhamella catarrhalis, Klebsiella ozaenae, Citrobacterintermedius, Pseudomonas fluorescens and Enterobacter aerogenes were isolated. Gram-positive bacteria were of Bacillus subtilis, B. megaterium and Micrococcus luteus. When plasmid curing was done using acredine orange, the resistance against penicillin-G, ampicillin, tetracycline, amoxycillin, kanamycin, and chloramphenicol were totally lost in all strains, which confirmed the role of plasmid in these strains against antibiotics. Ten strains belong to different species were selected for the plasmid isolation and electrophoresis was done. Presence of plasmids in all strains was confirmed and the molecular weight was in the range of 2850 to 3170 bp. The study revealed that MAR strains are common in Uppanar estuary and they are plasmid mediated. This environment is seemed to be deteriorating at an alarming rate.

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Available from: Thavasi Renga Thavasi
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    • "Because of its small size and its already proven versatility as part of a shuttle plasmid, pMCE2 appears to be a rather promising candidate as a cloning device and gene vehicle. By acridine orange-mediated curing, Thavasi et al. (2007) reported that the loss of a plasmid of approximately 2.8 kb from a marine M. luteus was accompanied by the loss of penicillin, ampicillin, tetracycline, amoxicillin, kanamycin , and chloramphenicol resistance (Table 1). Similarly, a 5.1-kb plasmid from a Micrococcus strain isolated from poultry litter conferred multiple antibiotic resistance (kanamycin , tetracycline, erythromycin, ampicillin, tobramycin, streptomycin, rifampicin, and chloramphenicol) that was transferable. "

    Full-text · Article · Jan 2013 · Applied Microbiology and Biotechnology
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    • "Because of its small size and its already proven versatility as part of a shuttle plasmid, pMCE2 appears to be a rather promising candidate as a cloning device and gene vehicle. By acridine orange-mediated curing, Thavasi et al. (2007) reported that the loss of a plasmid of approximately 2.8 kb from a marine M. luteus was accompanied by the loss of penicillin, ampicillin, tetracycline, amoxicillin, kanamycin , and chloramphenicol resistance (Table 1). Similarly, a 5.1-kb plasmid from a Micrococcus strain isolated from poultry litter conferred multiple antibiotic resistance (kanamycin , tetracycline, erythromycin, ampicillin, tobramycin, streptomycin, rifampicin, and chloramphenicol) that was transferable. "
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    ABSTRACT: Micrococci are Gram-positive G + C-rich, nonmotile, nonspore-forming actinomycetous bacteria. Micrococcus comprises ten members, with Micrococcus luteus being the type species. Representatives of the genus play important roles in the biodegradation of xenobiotics, bioremediation processes, production of biotechnologically important enzymes or bioactive compounds, as test strains in biological assays for lysozyme and antibiotics, and as infective agents in immunocompromised humans. The first description of plasmids dates back approximately 28 years, when several extrachromosomal elements ranging in size from 1.5 to 30.2 kb were found in Micrococcus luteus. Up to the present, a number of circular plasmids conferring antibiotic resistance, the ability to degrade aromatic compounds, and osmotolerance are known, as well as cryptic elements with unidentified functions. Here, we review the Micrococcus extrachromosomal traits reported thus far including phages and the only quite recently described large linear extrachromosomal genetic elements, termed linear plasmids, which range in size from 75 kb (pJD12) to 110 kb (pLMA1) and which confer putative advantageous capabilities, such as antibiotic or heavy metal resistances (inferred from sequence analyses and curing experiments). The role of the extrachromosomal elements for the frequently proven ecological and biotechnological versatility of the genus will be addressed as well as their potential for the development and use as genetic tools.
    Full-text · Article · Nov 2012 · Applied Microbiology and Biotechnology
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    • "Our isolates showed MAR profiles with 9 to 20 antibiotics; however, the number of antimicrobials to which strains were resistant was not necessarily related to the level of contamination of beaches, and this finding was not consistent, at least in part, with data reported by Oliveira et al.(35). MAR is found frequently in the marine environment (27, 30, 31, 35, 45), it is often plasmid mediated (45), and also can be the result of natural or acquired cross-resistance (14, 39). "
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    ABSTRACT: The aim of the study was to evaluate bacterial antibiotic resistance in seawater from four beaches in Algiers. The most significant resistance rates were observed for amoxicillin and ticarcillin, whereas they were relatively low for ceftazidime, cefotaxime and imipenem. According to sampling sites, the highest resistance rates were recorded for 2 sites subjected to chemical and microbiological inputs (amoxicillin, 43% and 52%; ticarcillin, 19.6% and 47.7%), and for 2 sites relatively preserved from anthropogenic influence, resistance rates were lowest (amoxicillin, 1.5% and 16%; ticarcillin, 0.8% and 2.6%). Thirty-four bacteria resistant to imipenem (n=14) or cefotaxime (n=20) were identified as Pseudomonas aeruginosa (n=15), Pseudomonas fluorescens (7), Stenotrophomonas maltophilia (4), Burkholderia cepacia (2), Bordetella sp. (1), Pantoea sp. (1), Acinetobacter baumannii (1), Chryseomonas luteola (1), Ochrobactrum anthropi (1) and Escherichia coli (1). Screening for extended spectrum β-lactamase showed the presence of CTX-M-15 β-lactamase in the E. coli isolate, and the encoding gene was transferable in association with the IncI1 plasmid of about 50 kbp. Insertion sequence ISEcp1B was located upstream of the CTX-M-15 gene. This work showed a significant level of resistance to antibiotics, mainly among environmental saprophytic bacteria. Transmissible CTX-M-15 was detected in E. coli; this may mean that contamination of the environment by resistant bacteria may cause the spread of resistance genes.
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