Isolation and molecular identification of mercury resistant bacteria and detection of Escherichia coli mercuric reductase gene from wastewater of Khowr-e-Musa, Iran

Abstract: Mercury-resistant bacteria can be found in the oral cavity, especially in dental plaques which are exposed to mercury in amalgam. Albeit, not all mercury resistant bacteria must be resistant to antibiotics. This study aimed to determine the level of the resistance of Escherichia coli in mercury and to determine whether the mercury-resistant bacteria have become resistant to the antibiotic ciprofloxacin. This study used a descriptive exploratory method with samples of Escherichia coli bacteria, mercury, and antibiotics that were available in the Laboratory of Pharmaceutical Microbiology University of Sam Ratulangi Manado. The bacterium E. coli were grown in four concentrations of mercury. The results showed that E. coli was resistant to mercury. However, in three repetitions of antibiotic it was found that E. coli was still sensitive to ciprofloxacin. Based on the results, it is advisable to do a similar study in groups using the same antibiotic but with different treatments.Keywords: mercury, bacteria, resistant, ciprofloxacin antibioticAbstrak: Bakteri resisten merkuri bisa ditemukan di dalam rongga mulut pada plak gigi yang terpapar merkuri (amalgam). Bakteri yang resisten merkuri tidak harus resisten terhadap antibiotic. Penelitian ini bertujuan untuk mengetahui tingkat resisensi bakteri Escherichia coli (E.coli) terhadap merkuri dan untuk mengetahui apakah bakteri yang resisten merkuri ini juga resisten terhadap antibiotik siprofloksasin. Penelitian ini menggunakan metode deskriptif eksploratif dengan sampel E.coli, merkuri, dan antibiotik yang tersedia di Laboratorium Mikrobiologi Farmasi Universitas Sam Ratulangi Manado. Hasil penelitian memperlihatkan bahwa E. coli yang ditanam pada empat konsentrasi merkuri resisten terhadap merkuri. Dari hasil uji resisten antibiotik dengan tiga kali pengulangan didapatkan bahwa E. coli yang resisten merkuri ini masih sensitif terhadap siprofloksasin. Berdasarkan hasil penelitian disarankan untuk dilakukan penelitian yang serupa secara berkelompok dengan menggunakan antibiotik yang sama tetapi dengan perlakuan yang berbeda.Kata kunci: merkuri, bakteri, resisten, antibiotik siprofloksasin

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Protein Method for Investigating Mercuric Reductase Gene Expression in Aquatic Environments

Applied and Environmental Microbiology ◽

10.1128/aem.64.2.695-702.1998 ◽

1998 ◽

Vol 64 (2) ◽

pp. 695-702 ◽

Cited By ~ 18

Author(s):

O. A. Ogunseitan

Keyword(s):

Gene Expression ◽

Colorimetric Assay ◽

Reductase Activity ◽

Molecular Techniques ◽

Resistant Bacteria ◽

Specific Gene ◽

Oxidoreductase Activity ◽

Mercuric Reductase ◽

Mercuric Ion ◽

Reductase Gene

A colorimetric assay for NADPH-dependent, mercuric ion-specific oxidoreductase activity was developed to facilitate the investigation of mercuric reductase gene expression in polluted aquatic ecosystems. Protein molecules extracted directly from unseeded freshwater and samples seeded with Pseudomonas aeruginosa PU21(Rip64) were quantitatively assayed for mercuric reductase activity in microtiter plates by stoichiometric coupling of mercuric ion reduction to a colorimetric redox chain through NADPH oxidation. Residual NADPH was determined by titration with phenazine methosulfate-catalyzed reduction of methyl thiazolyl tetrazolium to produce visible formazan. Spectrophotometric determination of formazan concentration showed a positive correlation with the amount of NADPH remaining in the reaction mixture (r 2 = 0.99). Mercuric reductase activity in the protein extracts was inversely related to the amount of NADPH remaining and to the amount of formazan produced. A qualitative nitrocellulose membrane-based version of the method was also developed, where regions of mercuric reductase activity remained colorless against a stained-membrane background. The assay detected induced mercuric reductase activity from 102 CFU, and up to threefold signal intensity was detected in seeded freshwater samples amended with mercury compared to that in mercury-free samples. The efficiency of extraction of bacterial proteins from the freshwater samples was (97 ± 2)% over the range of population densities investigated (102 to 108 CFU/ml). The method was validated by detection of enzyme activity in protein extracts of water samples from a polluted site harboring naturally occurring mercury-resistant bacteria. The new method is proposed as a supplement to the repertoire of molecular techniques available for assessing specific gene expression in heterogeneous microbial communities impacted by mercury pollution.

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STUDI POPULASI BAKTERI RESISTEN MERKURI DI DAERAH ALIRAN SUNGAI TONDANO, KELURAHAN KETANG BARU, MANADO

JURNAL ILMIAH SAINS ◽

10.35799/jis.11.1.2011.36 ◽

2011 ◽

Vol 11 (1) ◽

pp. 26

Author(s):

Aaltje E. Manampiring ◽

Billy J. Keppel

Keyword(s):

Escherichia Coli ◽

Mercury Resistance ◽

Resistant Bacteria ◽

Cross Sectional ◽

Watershed Area ◽

Descriptive Research ◽

Mercury Resistant Bacteria

Kadar merkuri yang tinggi di perairan umumnya dapat mempengaruhi keadaan biota termasuk bakteri yang resisten terhadap merkuri. Penelitian deskriptif yang menggunakan metode cross sectional bertujuan untuk menguji resistensi bakteri di aliran sungai Tondano, Kelurahan Ketang Baru, Manado terhadap merkuri. Escherichia coli dan Bacillus careus (isolat1,1 dan 2,2) hanya dapar tumbuh pada konsentrasi HgCl2 0,02%. Lactobacillus sp. dan Veillonella parvula (isolat 1,2 2,1 3,1 dan 3,2) tumbuh pada konsentrasi HgCl2 0,06%. Lactobacillus sp. (isolat 3,1) saja yang tumbuh pada konsentrasi HgCl2 0,1% dan tidak ada bakteri yang mampu tumbuh pada konsentrasi HgCl2 0,2%. STUDY ON POPULATION OF MERCURY-RESISTANT BACTERIAIN THE WATERSHED AREA OF TONDANO RIVER,KELURAHAN KETANG BARU, MANADOHigh concentration of mercury in the watershed area can affect biota condition, including mercury-resistant bacteria. This descriptive research with cross-sectional method aimed to evaluate the mercury-resistance of bacteria in watershed area of Tondano, Kelurahan Ketang Baru, Manado. Escherichia coli and Bacillus careus (isolates 1,1, dan 2,2) were able to grow in HgCl2 0,02%. Lactobacillus sp. and Veillonella parvula (isolates 1,2 2,1 3,1 and 3,2) grow in HgCl2 0,06%. Lactobacilus sp. (isolate 3,1) only grow in HgCl2 0,1% and none of bacteria could grow in HgCl2 0,2%.

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Faculty Opinions recommendation of Improving protein solubility: the use of the Escherichia coli dihydrofolate reductase gene as a fusion reporter.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1030480.359463 ◽

2006 ◽

Author(s):

David Waugh

Keyword(s):

Escherichia Coli ◽

Dihydrofolate Reductase ◽

Protein Solubility ◽

Reductase Gene

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Prevalence and Characterization of Extended-Spectrum β-Lactamase-Producing Antibiotic-Resistant Escherichia coli and Klebsiella pneumoniae in Ready-to-Eat Street Foods

Antibiotics ◽

10.3390/antibiotics10070850 ◽

2021 ◽

Vol 10 (7) ◽

pp. 850

Author(s):

Shobha Giri ◽

Vaishnavi Kudva ◽

Kalidas Shetty ◽

Veena Shetty

Keyword(s):

Escherichia Coli ◽

Food Safety ◽

Klebsiella Pneumoniae ◽

Rural Areas ◽

Significant Risk ◽

Microbiological Quality ◽

Resistant Bacteria ◽

Antibiotic Resistant ◽

E Coli ◽

Extended Spectrum

As the global urban populations increase with rapid migration from rural areas, ready-to-eat (RTE) street foods are posing food safety challenges where street foods are prepared with less structured food safety guidelines in small and roadside outlets. The increased presence of extended-spectrum-β-lactamase (ESBL) producing bacteria in street foods is a significant risk for human health because of its epidemiological significance. Escherichia coli and Klebsiella pneumoniae have become important and dangerous foodborne pathogens globally for their relevance to antibiotic resistance. The present study was undertaken to evaluate the potential burden of antibiotic-resistant E. coli and K. pneumoniae contaminating RTE street foods and to assess the microbiological quality of foods in a typical emerging and growing urban suburb of India where RTE street foods are rapidly establishing with public health implications. A total of 100 RTE food samples were collected of which, 22.88% were E. coli and 27.12% K. pneumoniae. The prevalence of ESBL-producing E. coli and K. pneumoniae was 25.42%, isolated mostly from chutneys, salads, paani puri, and chicken. Antimicrobial resistance was observed towards cefepime (72.9%), imipenem (55.9%), cefotaxime (52.5%), and meropenem (16.9%) with 86.44% of the isolates with MAR index above 0.22. Among β-lactamase encoding genes, blaTEM (40.68%) was the most prevalent followed by blaCTX (32.20%) and blaSHV (10.17%). blaNDM gene was detected in 20.34% of the isolates. This study indicated that contaminated RTE street foods present health risks to consumers and there is a high potential of transferring multi-drug-resistant bacteria from foods to humans and from person to person as pathogens or as commensal residents of the human gut leading to challenges for subsequent therapeutic treatments.

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Comparison of Antibiotic Resistance Profile of Escherichia coli between Pristine and Human-Impacted Sites in a River

Antibiotics ◽

10.3390/antibiotics10050575 ◽

2021 ◽

Vol 10 (5) ◽

pp. 575

Author(s):

Emi Nishimura ◽

Masateru Nishiyama ◽

Kei Nukazawa ◽

Yoshihiro Suzuki

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Resistant Bacteria ◽

Downstream Site ◽

Antibiotic Resistant Bacteria ◽

Antibiotic Resistant ◽

Upstream Site ◽

Resistance Profile ◽

Antibiotic Resistance Profile ◽

Significant Difference

Information on the actual existence of antibiotic-resistant bacteria in rivers where sewage, urban wastewater, and livestock wastewater do not load is essential to prevent the spread of antibiotic-resistant bacteria in water environments. This study compared the antibiotic resistance profile of Escherichia coli upstream and downstream of human habitation. The survey was conducted in the summer, winter, and spring seasons. Resistance to one or more antibiotics at upstream and downstream sites was on average 18% and 20%, respectively, and no significant difference was observed between the survey sites. The resistance rates at the upstream site (total of 98 isolated strains) to each antibiotic were cefazolin 17%, tetracycline 12%, and ampicillin 8%, in descending order. Conversely, for the downstream site (total of 89 isolated strains), the rates were ampicillin 16%, cefazolin 16%, and tetracycline 1% in descending order. The resistance rate of tetracycline in the downstream site was significantly lower than that of the upstream site. Furthermore, phylogenetic analysis revealed that many strains showed different resistance profiles even in the same cluster of the Pulsed-Field Gel Electrophoresis (PFGE) pattern. Moreover, the resistance profiles differed in the same cluster of the upstream and the downstream sites. In flowing from the upstream to the downstream site, it is plausible that E. coli transmitted or lacked the antibiotic resistance gene.

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Impact of On-Farm Interventions against CTX-Resistant Escherichia coli on the Contamination of Carcasses before and during an Experimental Slaughter

Antibiotics ◽

10.3390/antibiotics10030228 ◽

2021 ◽

Vol 10 (3) ◽

pp. 228

Author(s):

Michaela Projahn ◽

Jana Sachsenroeder ◽

Guido Correia-Carreira ◽

Evelyne Becker ◽

Annett Martin ◽

...

Keyword(s):

Escherichia Coli ◽

Broiler Chickens ◽

Stocking Density ◽

Resistant Bacteria ◽

Control Group ◽

Cross Contamination ◽

High Prevalence ◽

On Farm ◽

The Impact ◽

Slow Growing

Cefotaxime (CTX)-resistant Enterobacteriaceae are still an ongoing challenge in human and veterinary health. High prevalence of these resistant bacteria is detected in broiler chickens and the prevention of their dissemination along the production pyramid is of major concern. The impact of certain on-farm interventions on the external bacterial contamination of broiler chickens, as well as their influence on single processing steps and (cross-) contamination, have not yet been evaluated. Therefore, we investigated breast skin swab samples of broiler chickens before and during slaughter at an experimental slaughter facility. Broiler chickens were previously challenged with CTX-resistant Escherichia coli strains in a seeder-bird model and subjected to none (control group (CG)) or four different on-farm interventions: drinking water supplementation based on organic acids (DW), slow growing breed Rowan × Ranger (RR), reduced stocking density (25 kg/sqm) and competitive exclusion with Enterobacteriales strain IHIT36098(CE). Chickens of RR, 25 kg/sqm, and CE showed significant reductions of the external contamination compared to CG. The evaluation of a visual scoring system indicated that wet and dirty broiler chickens are more likely a vehicle for the dissemination of CTX-resistant and total Enterobacteriaceae into the slaughterhouses and contribute to higher rates of (cross-) contamination during processing.

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In vitro activity of antimicrobial peptide CDP-B11 alone and in combination with colistin against colistin-resistant and multidrug-resistant Escherichia coli

Scientific Reports ◽

10.1038/s41598-021-81140-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kaitlin S. Witherell ◽

Jason Price ◽

Ashok D. Bandaranayake ◽

James Olson ◽

Douglas R. Call

Keyword(s):

Escherichia Coli ◽

Antimicrobial Peptide ◽

Membrane Integrity ◽

Antibiotic Resistance Genes ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Multidrug Resistant Bacteria ◽

E Coli ◽

Minimal Media

AbstractMultidrug-resistant bacteria are a growing global concern, and with increasingly prevalent resistance to last line antibiotics such as colistin, it is imperative that alternative treatment options are identified. Herein we investigated the mechanism of action of a novel antimicrobial peptide (CDP-B11) and its effectiveness against multidrug-resistant bacteria including Escherichia coli #0346, which harbors multiple antibiotic-resistance genes, including mobilized colistin resistance gene (mcr-1). Bacterial membrane potential and membrane integrity assays, measured by flow cytometry, were used to test membrane disruption. Bacterial growth inhibition assays and time to kill assays measured the effectiveness of CDP-B11 alone and in combination with colistin against E. coli #0346 and other bacteria. Hemolysis assays were used to quantify the hemolytic effects of CDP-B11 alone and in combination with colistin. Findings show CDP-B11 disrupts the outer membrane of E. coli #0346. CDP-B11 with colistin inhibits the growth of E. coli #0346 at ≥ 10× lower colistin concentrations compared to colistin alone in Mueller–Hinton media and M9 media. Growth is significantly inhibited in other clinically relevant strains, such as Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae. In rich media and minimal media, the drug combination kills bacteria at a lower colistin concentration (1.25 μg/mL) compared to colistin alone (2.5 μg/mL). In minimal media, the combination is bactericidal with killing accelerated by up to 2 h compared to colistin alone. Importantly, no significant red blood hemolysis is evident for CDP-B11 alone or in combination with colistin. The characteristics of CDP-B11 presented here indicate that it can be used as a potential monotherapy or as combination therapy with colistin for the treatment of multidrug-resistant infections, including colistin-resistant infections.

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ESBL Activity, MDR, and Carbapenem Resistance among Predominant Enterobacterales Isolated in 2019

Antibiotics ◽

10.3390/antibiotics10060744 ◽

2021 ◽

Vol 10 (6) ◽

pp. 744

Author(s):

Altaf Bandy ◽

Bilal Tantry

Keyword(s):

Escherichia Coli ◽

Saudi Arabia ◽

Antimicrobial Resistance ◽

Carbapenem Resistance ◽

Resistant Bacteria ◽

Sociodemographic Characteristics ◽

Chi Square ◽

E Coli ◽

Chi Square Test ◽

Resistance Rates

Antimicrobial-resistance in Enterobacterales is a serious concern in Saudi Arabia. The present study retrospectively analyzed the antibiograms of Enterobacterales identified from 1 January 2019 to 31 December 2019 from a referral hospital in the Aljouf region of Saudi Arabia. The revised document of the Centers for Disease Control (CDC) CR-2015 and Magiorakos et al.’s document were used to define carbapenem resistance and classify resistant bacteria, respectively. The association of carbapenem resistance, MDR, and ESBL with various sociodemographic characteristics was assessed by the chi-square test and odds ratios. In total, 617 Enterobacterales were identified. The predominant (n = 533 (86.4%)) isolates consisted of 232 (37.6%), 200 (32.4%), and 101 (16.4%) Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, respectively. In general, 432 (81.0%) and 128 (24.0%) isolates were of MDR and ESBL, respectively. The MDR strains were recovered in higher frequency from intensive care units (OR = 3.24 (1.78–5.91); p < 0.01). E. coli and K. pneumoniae resistance rates to imipenem (2.55 (1.21–5.37); p < 0.01) and meropenem (2.18 (1.01–4.67); p < 0.04), respectively, were significantly higher in winter. The data emphasize that MDR isolates among Enterobacterales are highly prevalent. The studied Enterobacterales exhibited seasonal variation in antimicrobial resistance rates towards carbapenems and ESBL activity.

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