Antibacterial agents and heavy metal resistance in Gram-negative bacteria isolated from seawater, shrimp and sediment in Iskenderun Bay, Turkey

ABSTRACT A cluster of genes involved in antibiotic and heavy metal resistance has been characterized from a clinical isolate of the gram-negative bacterium Stenotrophomonas maltophilia. These genes include a macrolide phosphotransferase (mphBM) and a cadmium efflux determinant (cadA), together with the genecadC coding for its transcriptional regulator. ThecadC cadA region is flanked by a truncated IS257 sequence and a region coding for a bin3invertase. Despite their presence in a gram-negative bacterium, these genetic elements share a common gram-positive origin. The possible origin of these determinants as a remnant composite transposon as well as the role of gene transfer between gram-positive and gram-negative bacteria for the acquisition of antibiotic resistance determinants in chronic, mixed infections is discussed.

Download Full-text

Heavy-metal resistance in Gram-negative bacteria isolated from Kongsfjord, Arctic

Canadian Journal of Microbiology ◽

10.1139/cjm-2014-0803 ◽

2015 ◽

Vol 61 (6) ◽

pp. 429-435 ◽

Cited By ~ 18

Author(s):

C.S. Neethu ◽

K.M. Mujeeb Rahiman ◽

A.V. Saramma ◽

A.A. Mohamed Hatha

Keyword(s):

Heavy Metals ◽

Inhibitory Concentration ◽

Heavy Metal Resistance ◽

Metal Resistance ◽

The Arctic ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Isolation And Characterization ◽

Tube Dilution

Isolation and characterization of heterotrophic Gram-negative bacteria was carried out from the sediment and water samples collected from Kongsfjord, Arctic. In this study, the potential of Arctic bacteria to tolerate heavy metals that are of ecological significance to the Arctic (selenium (Se), mercury (Hg), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)) was investigated. Quantitative assay of 130 isolates by means of plate diffusion and tube dilution methods was carried out by incorporation of different concentrations of metals. Growth in Se and Pb at a concentration of 3000 μg/L was significantly lower (P ≤ 0.0001) than at 2000 μg/L. The minimum inhibitory concentration for Cd and Hg was 50 μg/L (P ≤ 0.0001, F = 264.23 and P ≤ 0.0001, F = 291.08, respectively) even though in the tube dilution test, Hg-containing tubes showed much less growth, revealing its superior toxicity to Cd. Thus, the level of toxicity of heavy metals was found to be in the order of Hg > Cd > Cu > Zn > Pb > Se. Multiple-metal-resistant isolates were investigated for their resistance against antibiotics, and a positive correlation was observed between antibiotic and metal resistance for all the isolates tested. The resistant organisms thus observed might influence the organic and inorganic cycles in the Arctic and affect the ecosystem.

Download Full-text

Aeromonas and Pseudomonas: antibiotic and heavy metal resistance species from Iskenderun Bay, Turkey (northeast Mediterranean Sea)

Environmental Monitoring and Assessment ◽

10.1007/s10661-009-1051-1 ◽

2009 ◽

Vol 167 (1-4) ◽

pp. 309-320 ◽

Cited By ~ 37

Author(s):

Fatih Matyar ◽

Tamer Akkan ◽

Yasemin Uçak ◽

Buse Eraslan

Keyword(s):

Heavy Metal ◽

Mediterranean Sea ◽

Heavy Metal Resistance ◽

Metal Resistance ◽

Iskenderun Bay

Download Full-text

Metals Removal and Recovery by Arthrobacter sp. Biomass

Water Science & Technology ◽

10.2166/wst.1992.0683 ◽

1992 ◽

Vol 26 (9-11) ◽

pp. 2149-2152 ◽

Cited By ~ 6

Author(s):

A. Grappelli ◽

L. Campanella ◽

E. Cardarelli ◽

F. Mazzei ◽

M. Cordatore ◽

...

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Industrial Wastes ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Real Possibility ◽

Metals Removal ◽

Metal Capture ◽

Accumulation Of Metals ◽

Removal And Recovery

Experiments on the real possibility of employing microorganisms to capture inorganic polluting substances, mainly heavy metals from urban and industrial wastes, are running using bacteria biomass. Many strains of Arthrobacter spp., gram-negative bacteria, diffused in the soil also inacondition of environmental stresses, have been proved to be particulary effective in heavy metal capture (Cd, Cr, Pb, Cu, Zn). The active and passive processes in accumulation of metals by bacteria were studied. Our experiments have been done on fluid biomass and on a membrane both for practical use and for an easy recovery.

Download Full-text

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.

Download Full-text

Apomorphine Targets the Pleiotropic Bacterial Regulator Hfq

Antibiotics ◽

10.3390/antibiotics10030257 ◽

2021 ◽

Vol 10 (3) ◽

pp. 257

Author(s):

Florian Turbant ◽

David Partouche ◽

Omar El Hamoui ◽

Sylvain Trépout ◽

Théa Legoubey ◽

...

Keyword(s):

Small Rnas ◽

Antibacterial Agents ◽

Amyloid Fibrils ◽

Noncoding Rnas ◽

Amyloid Formation ◽

Gram Negative Bacteria ◽

Translation Efficiency ◽

Gram Negative ◽

Bacterial Adaptation ◽

E Coli

Hfq is a bacterial regulator with key roles in gene expression. The protein notably regulates translation efficiency and RNA decay in Gram-negative bacteria, thanks to its binding to small regulatory noncoding RNAs. This property is of primary importance for bacterial adaptation and survival in hosts. Small RNAs and Hfq are, for instance, involved in the response to antibiotics. Previous work has shown that the E. coli Hfq C-terminal region (Hfq-CTR) self-assembles into an amyloid structure. It was also demonstrated that the green tea compound EpiGallo Catechin Gallate (EGCG) binds to Hfq-CTR amyloid fibrils and remodels them into nonamyloid structures. Thus, compounds that target the amyloid region of Hfq may be used as antibacterial agents. Here, we show that another compound that inhibits amyloid formation, apomorphine, may also serve as a new antibacterial. Our results provide an alternative in order to repurpose apomorphine, commonly used in the treatment of Parkinson’s disease, as an antibiotic to block bacterial adaptation to treat infections.

Download Full-text