scholarly journals Extreme Environments and High-Level Bacterial Tellurite Resistance

2019 ◽  
Vol 7 (12) ◽  
pp. 601 ◽  
Author(s):  
Chris Maltman ◽  
Vladimir Yurkov
Keyword(s):  
Extreme Environments ◽  
Pollutant Removal ◽  
The Other ◽  
Tellurite Resistance ◽  
Elemental Tellurium ◽  
E Coli ◽  
Resistance Reduction ◽  
High Level ◽  
The Impact ◽  
Level Resistance

Bacteria have long been known to possess resistance to the highly toxic oxyanion tellurite, most commonly though reduction to elemental tellurium. However, the majority of research has focused on the impact of this compound on microbes, namely E. coli, which have a very low level of resistance. Very little has been done regarding bacteria on the other end of the spectrum, with three to four orders of magnitude greater resistance than E. coli. With more focus on ecologically-friendly methods of pollutant removal, the use of bacteria for tellurite remediation, and possibly recovery, further highlights the importance of better understanding the effect on microbes, and approaches for resistance/reduction. The goal of this review is to compile current research on bacterial tellurite resistance, with a focus on high-level resistance by bacteria inhabiting extreme environments.

scholarly journals Antimicrobial Resistance of DiarrheagenicEscherichia coli Isolated from Children under the Age of 5 Years from Ifakara, Tanzania

1999 ◽  
Vol 43 (12) ◽  
pp. 3022-3024 ◽  
Author(s):  
Jordi Vila ◽  
Martha Vargas ◽  
Climent Casals ◽  
Honorato Urassa ◽  
Hassan Mshinda ◽  
...  
Keyword(s):  
Developing Countries ◽  
Public Health Problem ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Important Public Health Problem ◽  
Important Public Health ◽  
E Coli ◽  
High Level ◽  
Level Resistance ◽  
Children Under 5

ABSTRACT Diarrhea caused by multidrug-resistant bacteria is an important public health problem among children in developing countries. The prevalence and antimicrobial susceptibility of diarrheagenicEscherichia coli in 346 children under 5 years of age in Ifakara, Tanzania, were studied. Thirty-eight percent of the cases of diarrhea were due to multiresistant enterotoxigenic E. coli, enteroaggregative E. coli, or enteropathogenicE. coli. Strains of all three E. colicategories showed high-level resistance to ampicillin, tetracycline, co-trimoxazole, and chloramphenicol but were highly susceptible to quinolones. Guidelines for appropriate use of antibiotics in developing countries need updating.

scholarly journals Plasmid-mediated dissemination of the metallo-beta-lactamase gene blaIMP among clinically isolated strains of Serratia marcescens.

1995 ◽  
Vol 39 (4) ◽  
pp. 824-829 ◽  
Author(s):  
H Ito ◽  
Y Arakawa ◽  
S Ohsuka ◽  
R Wacharotayankun ◽  
N Kato ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
The Other ◽  
Beta Lactamase ◽  
Beta Lactams ◽  
E Coli ◽  
Aichi Prefecture ◽  
Imipenem Resistance ◽  
High Level ◽  
Lactamase Gene ◽  
Moderately Resistant

The distribution of strains producing metallo-beta-lactamase among 105 strains of Serratia marcescens was investigated. All of these strains were isolated in seven general hospitals located in Aichi Prefecture, Japan, from April to May 1993. Southern hybridization analysis suggested that four S. marcescens strains, AK9373, AK9374, AK9385, and AK9391, had a metallo-beta-lactamase genes similar to the blaIMP gene found by our laboratory (E. Osano, Y. Arakawa, R. Wacharotayankun, M. Ohta, T. Horii, H. Ito, F. Yoshimura, and N. Kato, Antimicrob. Agents Chemother. 38:71-78, 1994), and these four strains showed resistance to carbapenems as well as to the other broad-spectrum beta-lactams. In particular, strains AK9373, AK9374, and AK9391 showed an extraordinarily high-level resistance to imipenem (MICs, > or = 64 micrograms/ml), whereas strain AK9385 demonstrated moderate imipenem resistance (MIC, 8 micrograms/ml). The imipenem resistance of AK9373 was transferred to Escherichia coli CSH2 by conjugation with a frequency of 10(-5). The DNA probe of the blaIMP gene hybridized to a large plasmid (approximately 120 kb) transferred into the E. coli transconjugant as well as to the large plasmids harbored by AK9373. On the other hand, although we failed in the conjugational transfer of imipenem resistance from strains AK9374, AK9385, and AK9391 to E. coli CSH2, imipenem resistance was transferred from these strains to E. coli HB101 by transformation. A plasmid (approximately 25 kb) was observed in each transformant which acquired imipenem resistance. The amino acid sequence at the N terminus of the enzyme purified from strain AK9373 was identical to that of the metallo-beta-lactamase IMP-1. In contrast, strains ES9348, AK9386, and AK93101, which were moderately resistant to imipenem (MICs, > or = 4 to < or = 8 micrograms/ml), had no detectable blaIMP gene. As a conclusion, 19% of clinically isolated S. marcescens strains in Aichi Prefecture, Japan, in 1993 were resistant to imipenem (MICs, > or = 2 micrograms/ml), and strains which showed high-level imipenem resistance because of acquisition of a plasmid-mediated blaIMP-like metallo-beta-lactamase gene had already proliferated as nosocomial infections, at least in a general hospital.

Inactivation of chloramphenicol by Gram-negative microorganisms

1968 ◽  
Vol 14 (8) ◽  
pp. 891-899 ◽  
Author(s):  
David Sompolinsky ◽  
Ruth Ziegler-Schlomowitz ◽  
Dora Herczog
Keyword(s):  
Escherichia Coli ◽  
Growth Medium ◽  
Minimal Medium ◽  
Resistance Factor ◽  
The Other ◽  
Gram Negative ◽  
Resistant Strains ◽  
Gram Negative Organisms ◽  
High Level ◽  
Level Resistance

Two derivative strains of Escherichia coli with high-level resistance to chloramphenicol, one carrying an episomal resistance factor and the other a chromosomal mutant, were both shown to be potent inactivators of the drug. When 1 mM chloramphenicol was added to an exponential culture in minimal medium, growth was halted until 85–90% of the drug was inactivated by acylation. At this state the drug was essentially monoacylated. During and after growth, esterification of the second alcoholic group occurred, though at a slower rate. Arylamines, in amounts up to 10% of chloramphenicol equivalents, were demonstrated in the growth medium after 1–3 days' incubation.With an acetateless mutant of Escherichia coli K12, carrying a resistance factor, it was shown that 5–6 moles of acetate was consumed for every mole of chloramphenicol acylated.Inactivation of chloramphenicol by Gram-negative organisms from infections in hospitalized patients was also examined. Among 103 strains susceptible to chloramphenicol, none produced considerable amounts of chloramphenicol esters. The same was the case with 14 resistant strains of Pseudomonas. Of 134 other resistant organisms examined, including strains of Escherichia, Proteus, Klebsiella, Salmonella, and Shigella, 133 were producers of chloramphenicol esters, and in most cases the drug was partly or entirely diacylated.

scholarly journals Outbreak Caused by NDM-1- and RmtB-Producing Escherichia coli in Bulgaria

2014 ◽  
Vol 58 (4) ◽  
pp. 2472-2474 ◽  
Author(s):  
Laurent Poirel ◽  
Encho Savov ◽  
Arzu Nazli ◽  
Angelina Trifonova ◽  
Iva Todorova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
16S Rrna ◽  
Sequence Type ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant ◽  
The World ◽  
High Level ◽  
16S Rrna Methylase ◽  
Level Resistance

ABSTRACTTwelve consecutive carbapenem-resistantEscherichia coliisolates were recovered from patients (infection or colonization) hospitalized between March and September 2012 in different units at a hospital in Bulgaria. They all produced the carbapenemase NDM-1 and the extended-spectrum-β-lactamase CTX-M-15, together with the 16S rRNA methylase RmtB, conferring high-level resistance to all aminoglycosides. All those isolates were clonally related and belonged to the same sequence type, ST101. In addition to being the first to identify NDM-producing isolates in Bulgaria, this is the very first study reporting an outbreak of NDM-1-producingE. coliin the world.

scholarly journals Plasmid-Mediated Resistance to Extended-Spectrum Cephalosporins and Resistance to Fluoroquinolones in Escherichia Coli Isolates from Black-headed Gulls (Larus Ridibundus)

2021 ◽  
Author(s):  
Maja Velhner ◽  
Dalibor Todorović ◽  
Katarina Novović ◽  
Branko Jovčić ◽  
Gospava Lazić ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
E Coli ◽  
Extended Spectrum ◽  
Cephalosporin Antibiotics ◽  
High Level ◽  
Group D ◽  
Sequence Types ◽  
Replicon Type ◽  
Level Resistance ◽  
Game Animals

Abstract Although resistance to fluoroquinolones is common in E. coli isolates from farm and game animals in Serbia, currently no data are accessible on the occurrence of antibacterial resistances in E. coli isolates from gulls. Therefore, 45 cloacal swabs and 50 fecal samples from black-headed gulls were investigated for the presence of Escherichia coli isolates resistant to antibiotics. Multidrug resistance was detected in 22 E. coli isolates. High level resistance to fluoroquinolones was found in ten isolates with MIC values of ciprofloxacin ranging from 4 to 32 mg/L. Genotyping revealed single or double mutations in the quinolone resistance determining region (QRDR) of the gyrA or gyrA, parC and parE genes, respectively. Ten isolates showed resistance to extended-spectrum cephalosporin antibiotics. These ten isolates belonged to phylogenetic group B2 (five isolates), group D (four isolates) and group B1 (one isolate). An extended-spectrum β-lactamase resistance phenotype was detected in one isolate which carried the blaCTX-M-1 gene on a plasmid of the I2/FIB replicon type. Nine isolates carried blaCMY-2 genes, which were detected on conjugative plasmids in seven isolates. One transconjugant also carried hly, iroN, iss, ompT and cvaC virulence genes on the plasmid. Five different sequence types (ST38, ST2307, ST224, ST162 and ST34) were detected in E. coli isolates with ESBL or AmpC phenotype and genotype.

scholarly journals The role of Biofilm for Pseudomonas aeruginosa to resistance ultraviolet and MIC concentration for antibiotics

2012 ◽  
Vol 36 (0A) ◽  
pp. 13-19
Author(s):  
احمد محمد تركي
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
High Resistance ◽  
The Other ◽  
Bacterial Isolates ◽  
Staph Aureus ◽  
E Coli ◽  
The Impact ◽  
And Staphylococcus Aureus

The present study is conducted to in restigate the bacteria Pseudomonas aeruginosa, the impact of ultraviolet on the bacterial isolates under study and the resistance of these isolates to ultraviolet are studied in comparison to two standard isolates ( E . coli and Staphylococcus aureus ) which are considered sensitive to ultraviolet . The natures of the resistance of the isolates, under study, are also being investigated against the different antibiotics. The isolates are subjected to a test to examine their sensitivity to (12) types of antibiotics used routinely in the treatment of various infection of these bacteria. They are (streptomycin , cephalothin ,Gentamycin , cefotaxime ,nitrofurantion ,ampicillin, amoxicillin, rifampin, lincomycin, tetracycline, erythromycin and ciprofloxacin ).The lowest concentration installer ( MIC ) is also testified in accordance with six types of antibiotics (streptomycin, cefotaxime , rifampin , nitrofurantion , Gentamycin , amoxicillin ).The biologic effectiveness of the overlap between the bacterial isolates , under study, is examined against four bacteria (klebseilla pneumonia , Staphylococcus aureus , Enterobacter , Proteus ) The result of using the ultraviolet with different wavelength show the ability of the five local isolates used to resistance of ultraviolet reaching (180 s.) in comparison to the isolates E.coli and staph. aureus in which the ratio of killing is %100 at a time of exposing 40 , 60 sec. respectively. The results indicated that the five local bacterial isolates have high resistance to the most tested antibiotics, It is shouted that all of them have resistance to (erythromycin , tetracycline , lincomycin , Gentamycin ) but they are sensitive towards antibiotic streptomycin . as for the other antibiotics , over can find that the isolates are varied of them for being resisting or sensitive towards them .The results of testing the inhabited effectiveness of the five bacterial isolates towards some other bacterial isolates show the efficiency of the five local isolates in the inhabitation of growth of the five studied bacterial isolates.

scholarly journals Contribution of rpoB Mutations to Development of Rifamycin Cross-Resistance in Mycobacterium tuberculosis

1998 ◽  
Vol 42 (7) ◽  
pp. 1853-1857 ◽  
Author(s):  
D. L. Williams ◽  
L. Spring ◽  
L. Collins ◽  
L. P. Miller ◽  
L. B. Heifets ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Cross Resistance ◽  
In Vitro Mutagenesis ◽  
Missense Mutations ◽  
Resistance Mutations ◽  
Development Of Resistance ◽  
High Level ◽  
The Impact ◽  
Level Resistance

ABSTRACT The contributions of 23 insertion, deletion, or missense mutations within an 81-bp fragment of rpoB, the gene encoding the β-subunit of the DNA-dependent RNA polymerase of Mycobacterium tuberculosis, to the development of resistance to rifamycins (rifampin, rifabutin, rifapentine, and KRM-1648) in 29 rifampin-resistant clinical isolates were defined. Specific mutantrpoB alleles led to the development of cross-resistance to all rifamycins tested, while a subset of mutations were associated with resistance to rifampin and rifapentine but not to KRM-1648 or rifabutin. To further study the impact of specific rpoBmutant alleles on the development of rifamycin resistance, mutations were incorporated into the rpoB gene of M. tuberculosis H37Rv, contained on a mycobacterial shuttle plasmid, by in vitro mutagenesis. Recombinant M. tuberculosis clones containing plasmids with specific mutations in either codon 531 or 526 of rpoB exhibited high-level resistance to all rifamycins tested, whereas clones containing a plasmid with a mutation in codon 516 exhibited high-level resistance to rifampin and rifapentine but were susceptible to both rifabutin and KRM-1648. These results provided additional proof of the association of specificrpoB mutations with the development of rifamycin resistance and corroborate previous reports of the usefulness of rpoB genotyping for predicting rifamycin-resistant phenotypes.

scholarly journals Transferable high-level trimethoprim resistance among isolates ofEscherichia colifrom urinary tract infections in Ontario, Canada

1992 ◽  
Vol 109 (3) ◽  
pp. 473-481 ◽  
Author(s):  
N. Harnett
Keyword(s):  
Nalidixic Acid ◽  
Antimicrobial Agents ◽  
Acid Resistance ◽  
The Public ◽  
E Coli ◽  
High Level ◽  
Tract Infections ◽  
K 12 ◽  
Level Resistance ◽  
Nalidixic Acid Resistance

SUMMARYOf 1171 isolates ofEscherichia coliisolated from urine samples at the Public Health Laboratory, Toronto, Ontario, Canada, between May 1990 and December 1991, 120 (10·3%) were resistant to trimethoprim (TMP), cotrimoxazole (TMP/SMX), sulfamethoxazole (SMX) and other antimicrobial agents; 110 of the 120 isolates (91·7%) were resistant to four or more agents. The majority of resistant isolates (91·7%) exhibited high-level resistance (MIC > 1000 mg/L) to TMP. The MIC of TMP/SMX for all 120 isolates was > 2·0/38·0 mg/L and for SMX > 1024 mg/L. High-level resistances were also present among the β-lactam antimicrobials with MICs ranging from 16- > 256 mg/L. Forty-three of 120 TMP-resistant (35·8%) isolates conjugally transferred TMP-resistance toE. coliK-12. Co-transfer of several other resistances was observed. SMX cotransferred from 86% of the 43 donors and β-lactams together with SMX cotransferred from 70%. Nalidixic acid resistance was present among 22 (18·3%) of the 120 resistant isolates, however, nalidixic acid resistance was not transferred toE. coliK-12.

scholarly journals Trimethoprim-resistant mutants ofE. coliK12: preliminary genetic mapping

1975 ◽  
Vol 25 (3) ◽  
pp. 207-214 ◽  
Author(s):  
A. S. Breeze ◽  
P. Sims ◽  
K. A. Stacey
Keyword(s):  
Genetic Mapping ◽  
Structural Gene ◽  
Dihydrofolate Reductase ◽  
Bacteriophage P1 ◽  
E Coli ◽  
Resistant Mutants ◽  
High Level ◽  
Increased Activity ◽  
Level Resistance ◽  
Target Enzyme

SUMMARYTrimethoprim-resistant mutants ofE. coliK12 have been isolated by-serial subculture in progressively higher concentrations of trimethoprim. High-level resistance depends on the accumulation of several mutational changes. Transduction with bacteriophage P1 has shown that all the mutations involved in resistance are associated with a locus, to be calledtmr, betweenpyr AandpdxAand closely linked topdxA. Resistance is accompanied by, and presumably due to, an increased activity of the target enzyme, dihydrofolate reductase. Thetmrlocus may include the structural gene for dihydrofolate reductase but the only mutations that have so far been observed are concerned with regulation.

scholarly journals Human isolates of apramycin-resistant Escherichia coli which contain the genes for the AAC(3)IV enzyme

1993 ◽  
Vol 110 (2) ◽  
pp. 253-259 ◽  
Author(s):  
J. E. B. Hunter ◽  
C. A. Hart ◽  
J. C. Shelley ◽  
J. R. Walton ◽  
M. Bennett
Keyword(s):  
Escherichia Coli ◽  
Minimal Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Aminoglycoside Antibiotic ◽  
Dna Probe ◽  
Conjugative Plasmid ◽  
E Coli ◽  
High Level ◽  
Level Resistance

SUMMARYGentamicin-resistant Escherichia coli isolated at different periods from patients in two hospitals were tested for resistance to the aminoglycoside antibiotic apramycin. Twenty-four of 93 (26%) gentamicin-resistant isolates collected from the Royal Liverpool Hospital between 1981 and 1990 were resistant to apramycin. Thirteen isolates were highly resistant to apramycin (minimal inhibitory concentration (MIC) ≥ 1024 μg/ml). were also resistant to gentamicin, netilmicin and tobramycin, and hybridized with a DNA probe derived from the aminoglycoside acetyltransferase (3)IV (AAC(3)IV) gene. The proportion of gentamicinresistant isolates which had high level resistance to apramycin increased from 7% in 1981–5 to 24% in 1986–90.Twelve gentamicin-resistant E. coli from Guy's and St Thomas's Hospital isolated between 1977 and 1980 were also tested for resistance to apramycin. For five of these isolates the MICs of apramycin was 32–256 μg/ml. None was shown to have a conjugative plasmid carrying resistance to apramycin and only one hybridized with the DNA probe for the AAC(3)IV enzyme.

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