Heavy Metal Tolerance of Fe(III)-Reducing Microbial Communities in Contaminated Creek Bank Soils

ABSTRACTFe(III)-reducing soil enrichment cultures can tolerate 100 μM Cu and Cd, 150 μM Co, 600 μM Ni, and 2,500 μM Zn. Metal-tolerant cultures were dominated byGeobacter-relatedDeltaproteobacteriaand Gram-positiveFirmicutesspp.(ClostridiaandSedimentibacter). A Cd- and Cu-tolerant Fe(III)-reducing coculture ofDesulfosporosinusandDesulfitobacteriumindicated the importance of theFirmicutesfor Fe(III) reduction in the presence of metals.

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Draft Genome Sequence of the Phosphate-Solubilizing Rhizobacterium Burkholderia pseudomultivorans Strain MPSB1, Isolated from a Copper Mined-Out Site

Microbiology Resource Announcements ◽

10.1128/mra.01304-20 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Berna Lou L. Aba-Regis ◽

Kristel Mae P. Oliveros ◽

Cherry Ibarra-Romero ◽

Asuncion K. Raymundo ◽

Nelly S. Aggangan ◽

...

Keyword(s):

Heavy Metal ◽

Soil Sample ◽

Genome Sequence ◽

Phosphate Solubilization ◽

Metal Tolerance ◽

Draft Genome ◽

Heavy Metal Tolerance ◽

Draft Genome Sequence ◽

Content Type ◽

Phosphate Solubilizing

ABSTRACT Burkholderia pseudomultivorans MPSB1 was isolated from a copper mined-out soil sample collected from Mogpog, Marinduque, Philippines. Here, we report the draft genome sequence with predicted gene inventories supporting rhizosphere bioremediation, such as heavy metal tolerance, phosphate solubilization, and siderophore production.

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In -Vitro Antibiotic Resistance and Heavy Metal Tolerance Patterns of Gram-Positive and Gram-Negative Bacteria Isolated From Effluent Treated Water of Delhi, India.

Journal of Current Pharma Research ◽

10.33786/jcpr.2015.v05i02.006 ◽

2015 ◽

Vol 5 (2) ◽

pp. 1449-1458 ◽

Cited By ~ 8

Author(s):

Abhishek Chauhan . ◽

Pankaj Goyal . ◽

Ajit Varma . ◽

Tanu Jindal .

Keyword(s):

Heavy Metal ◽

Antibiotic Resistance ◽

Metal Tolerance ◽

Heavy Metal Tolerance ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Treated Water

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In-Feed Use of Heavy Metal Micronutrients in U.S. Swine Production Systems and Its Role in Persistence of Multidrug-Resistant Salmonellae

Applied and Environmental Microbiology ◽

10.1128/aem.04283-13 ◽

2014 ◽

Vol 80 (7) ◽

pp. 2317-2325 ◽

Cited By ~ 45

Author(s):

Julius J. Medardus ◽

Bayleyegn Z. Molla ◽

Matthew Nicol ◽

W. Morgan Morrow ◽

Paivi J. Rajala-Schultz ◽

...

Keyword(s):

Public Health ◽

Heavy Metal ◽

Production Systems ◽

Metal Tolerance ◽

Strong Association ◽

Heavy Metal Tolerance ◽

Multidrug Resistant ◽

Content Type ◽

Agar Dilution ◽

Metal Micronutrients

ABSTRACTThe study aimed to characterize the role of heavy metal micronutrients in swine feed in emergence of heavy-metal-tolerant and multidrug-resistantSalmonellaorganisms. We conducted a longitudinal study in 36 swine barns over a 2-year period. The feed and fecal levels of Cu2+and Zn2+were measured.Salmonellawas isolated at early and late finishing. MICs of copper sulfate and zinc chloride were measured using agar dilution. Antimicrobial susceptibility was tested using the Kirby-Bauer method, and 283 isolates were serotyped. We amplifiedpcoAandczcDgenes that encode Cu2+and Zn2+tolerance, respectively. Of the 283 isolates, 113 (48%) showed Cu2+tolerance at 24 mM and 164 (58%) showed Zn2+tolerance at 8 mM. In multivariate analysis, serotype and source of isolates were significantly associated with Cu2+tolerance (P< 0.001). Fecal isolates were more likely to be Cu2+tolerant than those of feed origin (odds ratio [OR], 27.0; 95% confidence interval [CI], 2.8 to 250;P= 0.0042) or environmental origin (OR, 5.8), implying the significance of gastrointestinal selective pressure.Salmonella entericaserotypes Typhimurium and Heidelberg, highly significant for public health, had higher odds of having >20 mM MICs of Cu2+than did “other” serotypes. More than 60% ofSalmonellaisolates with resistance type (R-type) AmStTeKm (32 of 53) carriedpcoA; only 5% with R-type AmClStSuTe carried this gene.czcDgene carriage was significantly associated with a higher Zn2+MIC (P< 0.05). The odds of having a high Zn2+MIC (≥8 mM) were 14.66 times higher in isolates with R-type AmClStSuTe than in those with R-type AmStTeKm (P< 0.05). The findings demonstrate strong association between heavy metal tolerance and antimicrobial resistance, particularly amongSalmonellaserotypes important in public health.

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Susceptibility of Methicillin-Resistant and -SusceptibleStaphylococcus aureusIsolates of Various Clonal Lineages from Germany to Eight Biocides

Applied and Environmental Microbiology ◽

10.1128/aem.00799-18 ◽

2018 ◽

Vol 84 (13) ◽

Cited By ~ 2

Author(s):

Isa Adriana Kernberger-Fischer ◽

Carsten Krischek ◽

Birgit Strommenger ◽

Ulrike Fiegen ◽

Martin Beyerbach ◽

...

Keyword(s):

Heavy Metal ◽

Metal Tolerance ◽

Heavy Metal Tolerance ◽

Sequence Type ◽

Animal Origin ◽

Methicillin Resistant ◽

Content Type ◽

Benzethonium Chloride ◽

Broth Microdilution Method ◽

Animal Isolates

ABSTRACTFew studies have been conducted on the susceptibility of bacteria to biocides. A total of 182 methicillin-resistant and -susceptibleStaphylococcus aureusisolates collected from healthy or diseased humans and animals in Germany were included in the present study. Sixty-three isolates of animal origin and 119 human isolates were tested for their MICs to eight biocides or heavy metals by the broth microdilution method. The MIC50and MIC90values of human and animal isolates were equal or differed by not more than 1 dilution step, and statistical analysis revealed that differences between MICs of human and animal isolates were not significant. However, when taking into account the multilocus sequence type (MLST), a strong tendency (P= 0.054) to higher MICs of silver nitrate was detected for clonal complex 398 (CC398) isolates from humans compared to those from animals. Furthermore, a comparison of MIC values from isolates belonging to different clonal lineages revealed that important human lineages such as CC22 and CC5 exhibited significantly (P< 0.05) higher MICs for the biocides chlorhexidine, benzethonium chloride, and acriflavine than the main animal lineage sequence type 398 (ST398). Isolates with elevated MIC values were tested for the presence of biocide and heavy metal tolerance-mediating genes by PCR assays, and the following genes were detected:mepA(n[no. of isolates containing the gene] = 44),lmrS(n= 36),norA(n= 35),sepA(n= 22),mco(n= 5),czrC(n= 3),smr(n= 2),copA(n= 1),qacAand/or -B(n= 1),qacG(n= 2), andqacJ(n= 1). However, only for some compounds was a correlation between the presence of a biocide tolerance gene and the level of MIC values detected.IMPORTANCEBiocides play an essential role in controlling the growth of microorganisms and the dissemination of nosocomial pathogens. In this study, we determined the susceptibility of methicillin-resistant and -susceptibleS. aureusisolates from humans and animals to various biocides and heavy metal ions and analyzed differences in susceptibilities between important clonal lineages. In addition, the presence of biocide or heavy metal tolerance-mediating genes was investigated. We demonstrated that important human lineages such as CC22 and CC5 had significantly higher MIC values for chlorhexidine, benzethonium chloride, and acriflavine than the main farm animal lineage, ST398. In addition, it was shown that for some combinations of biocides and tolerance genes, significantly higher MICs were detected for carriers. These findings provide new insights intoS. aureusbiocide and heavy metal tolerance.

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Heavy Metal Tolerance Trend in Extended-Spectrum β-Lactamase Encoding Strains Recovered from Food Samples

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18094718 ◽

2021 ◽

Vol 18 (9) ◽

pp. 4718

Author(s):

Kashaf Junaid ◽

Hasan Ejaz ◽

Iram Asim ◽

Sonia Younas ◽

Humaira Yasmeen ◽

...

Keyword(s):

Heavy Metal ◽

Metal Tolerance ◽

Heavy Metal Tolerance ◽

Heavy Metal Resistance ◽

Metal Resistance ◽

Food Samples ◽

Esbl Production ◽

Extended Spectrum ◽

Retail Food ◽

Esbl Producers

This study evaluates bacteriological profiles in ready-to-eat (RTE) foods and assesses antibiotic resistance, extended-spectrum β-lactamase (ESBL) production by gram-negative bacteria, and heavy metal tolerance. In total, 436 retail food samples were collected and cultured. The isolates were screened for ESBL production and molecular detection of ESBL-encoding genes. Furthermore, all isolates were evaluated for heavy metal tolerance. From 352 culture-positive samples, 406 g-negative bacteria were identified. Raw food samples were more often contaminated than refined food (84.71% vs. 76.32%). The predominant isolates were Klebsiella pneumoniae (n = 76), Enterobacter cloacae (n = 58), and Escherichia coli (n = 56). Overall, the percentage of ESBL producers was higher in raw food samples, although higher occurrences of ESBL-producing E. coli (p = 0.01) and Pseudomonas aeruginosa (p = 0.02) were observed in processed food samples. However, the prevalence of ESBL-producing Citrobacter freundii in raw food samples was high (p = 0.03). Among the isolates, 55% were blaCTX-M, 26% were blaSHV, and 19% were blaTEM. Notably, heavy metal resistance was highly prevalent in ESBL producers. These findings demonstrate that retail food samples are exposed to contaminants including antibiotics and heavy metals, endangering consumers.

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Evaluation of bacterial strains isolated from Late Quaternary alluvial sediments spanning ~ 28 m in depth for heavy metal tolerance and Cr(VI) removal ability

International Microbiology ◽

10.1007/s10123-021-00174-0 ◽

2021 ◽

Author(s):

Abhi P. Shah ◽

G. Archana

Keyword(s):

Heavy Metal ◽

Metal Tolerance ◽

Late Quaternary ◽

Heavy Metal Tolerance ◽

Bacterial Strains ◽

Alluvial Sediments

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Effect of Lead and Copper on Photosynthetic Apparatus in Citrus (Citrus aurantium L.) Plants. The Role of Antioxidants in Oxidative Damage as a Response to Heavy Metal Stress

Plants ◽

10.3390/plants10010155 ◽

2021 ◽

Vol 10 (1) ◽

pp. 155

Author(s):

Anastasia Giannakoula ◽

Ioannis Therios ◽

Christos Chatzissavvidis

Keyword(s):

Oxidative Stress ◽

Lipid Peroxidation ◽

Heavy Metal ◽

Metal Tolerance ◽

Heavy Metal Tolerance ◽

Membrane Integrity ◽

Photosynthetic Apparatus ◽

Heavy Metal Stress ◽

Photosynthetic Parameters ◽

Citrus Aurantium

Photosynthetic changes and antioxidant activity to oxidative stress were evaluated in sour orange (Citrus aurantium L.) leaves subjected to lead (Pb), copper (Cu) and also Pb + Cu toxicity treatments, in order to elucidate the mechanisms involved in heavy metal tolerance. The simultaneous effect of Pb− and Cu on growth, concentration of malondialdehyde (MDA), hydrogen peroxide (H2O2), chlorophylls, flavonoids, carotenoids, phenolics, chlorophyll fluorescence and photosynthetic parameters were examined in leaves of Citrus aurantium L. plants. Exogenous application of Pb and Cu resulted in an increase in leaf H2O2 and lipid peroxidation (MDA). Toxicity symptoms of both Pb and Cu treated plants were stunted growth and decreased pigments concentration. Furthermore, photosynthetic activity of treated plants exhibited a significant decline. The inhibition of growth in Pb and Cu-treated plants was accompanied by oxidative stress, as indicated by the enhanced lipid peroxidation and the high H2O2 concentration. Furthermore, antioxidants in citrus plants after exposure to high Pb and Cu concentrations were significantly increased compared to control and low Pb and Cu treatments. In conclusion, this study indicates that Pb and Cu promote lipid peroxidation, disrupt membrane integrity, reduces growth and photosynthesis and inhibit mineral nutrition. Considering the potential for adverse human health effects associated with high concentrations of Pb and Cu contained in edible parts of citrus plants the study signals that it is important to conduct further research into the accessibility and uptake of the tested heavy metals in the soil and whether they pose risks to humans.

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