Antibiotic resistance among bacteria isolated from seawater and penguin fecal samples collected near Palmer Station, AntarcticaThis article is one of a selection of papers in the Special Issue on Polar and Alpine Microbiology.

2009 ◽  
Vol 55 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Robert V. Miller ◽  
Katharine Gammon ◽  
Martin J. Day
Keyword(s):  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
Antarctic Waters ◽  
Colony Forming Units ◽  
Palmer Station ◽  
Human Habitation ◽  
The Antarctic

Antibiotic resistance in aquatic bacteria has increased steadily as a consequence of the widespread use of antibiotics, but practice and international treaty should have limited antibiotic contamination in Antarctica. We estimated antibiotic resistance in microorganisms isolated from the Antarctic marine waters and a penguin rookery, for 2 reasons: (i) as a measure of human impact and (ii) as a potential “snapshot” of the preantibiotic world. Samples were taken at 4 established sampling sites near Palmer Station, which is situated at the southern end of the Palmer Archipelago (64°10′S, 61°50′W). Sites were chosen to provide different potentials for human contamination. Forty 50 mL samples of seawater were collected and colony-forming units (CFU)/mL were determined at 6 and 20 °C. For this study, presumed psychrophiles (growth at 6 °C) were assumed to be native to Antarctic waters, whereas presumed mesophiles (growth at 20 °C but not at 6 °C) were taken to represent introduced organisms. The 20–6 °C CFU/mL ratio was used as a measure of the relative impact to the ecosystem of presumably introduced organisms. This ratio was highest at the site nearest to Palmer Station and decreased with distance from it, suggesting that human presence has impacted the natural microbial flora of the site. The frequency of resistance to 5 common antibiotics was determined in each group of isolates. Overall drug resistance was higher among the presumed mesophiles than the presumed psychrophiles and increased with proximity to Palmer Station, with the presumed mesophiles showing higher frequencies of single and multiple drug resistance than the psychrophile population. The frequency of multidrug resistance followed the same pattern. It appears that multidrug resistance is low among native Antarctic bacteria but is increased by human habitation.

scholarly journals Isolation, Molecular Identification and Multidrug Resistance Profiling of Bacteria Causing Clinical Mastitis in Cows

2020 ◽  
Author(s):  
D.J. Vatalia ◽  
B.B. Bhanderi ◽  
V.R. Nimavat ◽  
M.K. Jhala
Keyword(s):  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Multiple Drug Resistance ◽  
Bacterial Species ◽  
Research Work ◽  
Resistance Index ◽  
Diffusion Method ◽  
Multiple Drug ◽  
Milk Samples ◽  
Sensitivity Pattern

Background: Mastitis, the inflammation of parenchyma of mammary gland is frequently considered to be costliest and complex disease prevalent in India. Mastitis is caused by pathogens like Staphylococcus spp., Streptococcus spp., Mycoplasma bovis, E. coli, Klebsiella spp., Citrobacter spp., Enterobacter spp. and Entercoccus. The treatment of mastitis in animals is carried out using antibiotics. Treatment failure in mastitis is due to increased antibiotic resistance of mastitis pathogens and also due to indiscriminate use of antibiotics without testing in vitro antibiotic sensitivity test against causal organisms. In comparison to cultural method, PCR assays takes less time for detection of bacteria from the mastitis milk samples. Present research work was carried out regarding isolation, identification and multiple drug resistance profile of clinical bovine mastitis associated pathogens using conventional as well as molecular approach. Methods: In the present study, 73 mastitis milk samples were collected from Anand and Panchmahal district of Gujarat. The milk samples were subjected for cultural isolation and DNA extraction for identification of bacteria by cultural and PCR method. Antimicrobial sensitivity pattern of the isolates were carried by disc diffusion method and isolates were categorized in multiple drug resistant. Result: In the present study, Out of 73 mastitis milk samples collected from cows 48 (65.75%) cows were positive for bacterial isolation and S. aureus was the most predominant bacterial species. PCR from the mastitis milk additionally detected bacteria in culturally negative milk samples. Most sensitive drug was gentamicin and most of the isolates (90.19%) showed the multiple drug resistance for the two to nine drugs with 0.1 to 0.6 multiple antibiotic resistance index.

scholarly journals Advanced molecular characterization of enteropathogenic Escherichia coli isolated from diarrheic camel neonates in Egypt

2021 ◽  
Vol 14 (1) ◽  
pp. 85-91
Author(s):  
Momtaz A. Shahein ◽  
Amany N. Dapgh ◽  
Essam Kamel ◽  
Samah F. Ali ◽  
Eman A. Khairy ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Multiple Drug Resistance ◽  
Microbial Pathogens ◽  
Multiple Drug ◽  
Gastrointestinal Infections ◽  
Fecal Samples ◽  
E Coli

Background and Aim: Camels are important livestock in Egypt on cultural and economic bases, but studies of etiological agents of camelid diseases are limited. The enteropathogen Escherichia coli is a cause of broad spectrum gastrointestinal infections among humans and animals, especially in developing countries. Severe infections can lead to death. The current study aimed to identify pathogenic E. coli strains that cause diarrhea in camel calves and characterize their virulence and drug resistance at a molecular level. Materials and Methods: Seventy fecal samples were collected from diarrheic neonatal camel calves in Giza Governorate during 2018-2019. Samples were cultured on a selective medium for E. coli, and positive colonies were confirmed biochemically, serotyped, and tested for antibiotic susceptibility. E. coli isolates were further confirmed through detection of the housekeeping gene, yaiO, and examined for the presence of virulence genes; traT and fimH and for genes responsible for antibiotic resistance, ampC, aadB, and mphA. The isolates in the important isolated serotype, E. coli O26, were examined for toxigenic genes and sequenced. Results: The bacteriological and biochemical examination identified 12 E. coli isolates from 70 fecal samples (17.1%). Serotyping of these isolates showed four types: O26, four isolates, 33.3%; O103, O111, three isolates each, 25%; and O45, two isolates, 16.7%. The isolates showed resistance to vancomycin (75%) and ampicillin (66.6%), but were highly susceptible to ciprofloxacin, norfloxacin, and tetracycline (100%). The structural gene, yaiO (115 bp), was amplified from all 12 E. coli isolates and traT and fimH genes were amplified from 10 and 8 isolates, respectively. Antibiotic resistance genes, ampC, mphA, and aadB, were harbored in 9 (75%), 8 (66.6%), and 5 (41.7%), respectively. Seven isolates (58.3%) were MDR. Real-time-polymerase chain reaction of the O26 isolates identified one isolate harboring vt1, two with vt2, and one isolate with neither gene. Sequencing of the isolates revealed similarities to E. coli O157 strains. Conclusion: Camels and other livestock suffer various diseases, including diarrhea often caused by microbial pathogens. Enteropathogenic E. coli serotypes were isolated from diarrheic neonatal camel calves. These isolates exhibited virulence and multiple drug resistance genes.

Different Efflux Transporter Affinity and Metabolism of 99mTc-2-methoxyisobutylisonitrile and 99mTc-Tetrofosmin for Multidrug Resistance Monitoring in Cancer Cells

2018 ◽  
Author(s):  
Masato Kobayashi ◽  
Takafumi Tsujiuchi ◽  
Yuya Okui ◽  
Asuka Mizutani ◽  
Kodai Nishi ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Multidrug Resistance ◽  
Cancer Cells ◽  
Human Liver ◽  
High Stability ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
Labeled Compounds ◽  
Cancer Resistance ◽  
99Mtc Mibi

Objectives: Little is known about the affinity of 99mTc-labeled 2-methoxyisobutylisonitrile (99mTc-MIBI) and tetrofosmin (99mTc-TF) for multiple drug resistance in cancer cells. Additionally, if 99mTc-labeled compounds are metabolized immediately after injection, imaging with these compounds may not allow monitoring of multiple drug resistance in cancer cells. We examined the affinity of 99mTc-labeled compounds for these transporters and their stability in vivo. Methods: 99mTc-MIBI or 99mTc-TF was incubated in vesicles expressing P-glycoprotein (MDR1), multidrug resistance-associated protein (MRP)1-4, or breast cancer resistance protein with and without verapamil (MDR1 inhibitor) or MK-571 (MRP inhibitor). Time activity curves of 99mTc-labeled compounds were established using SK-N-SH neuroblastoma, SK-MEL-28 melanoma, and PC-3 prostate adenocarcinoma cell lines, and transporter expression of multiple drug resistance was measured in these cells. The stability of 99mTc-labeled compounds was evaluated in mice and human liver S9 fractions. Results: In vesicles, 99mTc-labeled compounds had affinity for MDR1 and MRP1. 99mTc-TF had additional affinity for MRP2 and MRP3. In SK-N-SH cells expressing MDR1 and MRP1, MK-571 produced the highest uptake of both 99mTc-labeled compounds. 99mTc-MIBI uptake with inhibitors was higher than 99mTc-TF uptake with inhibitors. 99mTc-TF was taken up more in SK-MEL-28 cells expressing MRP1 and MRP2 than PC-3 cells expressing MRP1 and MRP3. 99mTc-MIBI was metabolized after a 30-min incubation in SK-N-SH cells, mouse liver, human liver S9 fractions, and plasma. 99mTc-TF had high stability. Conclusion: 99mTc-MIBI is exported via MDR1 and MRP1 (MRP1 > MDR1) at greater levels and more quickly compared to 99mTc-TF, which is exported via MDR1 and MRP1-3 (MRP1 > MDR1; MRP1, 2 > MRP3). Although 99mTc-MIBI is metabolized, clinical imaging for monitoring MDR and shorter examination times may be possible with an earlier scanning time on late phase imaging. 99mTc-TF has high stability and accurately reflects the function of MDR1 and MRP1-3.

scholarly journals Multidrug Therapy and Evolution of Antibiotic Resistance: When Order Matters

2012 ◽  
Vol 78 (17) ◽  
pp. 6137-6142 ◽  
Author(s):  
Gabriel G. Perron ◽  
Sergey Kryazhimskiy ◽  
Daniel P. Rice ◽  
Angus Buckling
Keyword(s):  
Drug Resistance ◽  
Multidrug Resistance ◽  
Pathogenic Bacteria ◽  
Health Workers ◽  
Multiple Drug Resistance ◽  
Sequential Therapy ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Multidrug Therapy

ABSTRACTThe evolution of drug resistance among pathogenic bacteria has led public health workers to rely increasingly on multidrug therapy to treat infections. Here, we compare the efficacy of combination therapy (i.e., using two antibiotics simultaneously) and sequential therapy (i.e., switching two antibiotics) in minimizing the evolution of multidrug resistance. Usingin vitroexperiments, we show that the sequential use of two antibiotics againstPseudomonas aeruginosacan slow down the evolution of multiple-drug resistance when the two antibiotics are used in a specific order. A simple population dynamics model reveals that using an antibiotic associated with high costs of resistance first minimizes the chance of multidrug resistance evolution during sequential therapy under limited mutation supply rate. As well as presenting a novel approach to multidrug therapy, this work shows that costs of resistance not only influences the persistence of antibiotic-resistant bacteria but also plays an important role in the emergence of resistance.

Intrinsic antibiotic resistance in chickpea (Cicer arietinum) rhizobia

1985 ◽  
Vol 105 (1) ◽  
pp. 85-89 ◽  
Author(s):  
F. C. Garg ◽  
N. Beri ◽  
P. Tauro
Keyword(s):  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Cicer Arietinum ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
Wild Type

SUMMARYMore than 200 wild type isolates of chickpea (C. arietinum) rhizobia were screened for their drug resistance. Only 15 were found to be resistant to one or more antibiotics at a concentration of 5 μg/ml (units/ml). When tested for multiple drug resistance, some were found to be resistant to more than one antibiotic. In competition studies, rhizobia resistant to streptomycin were found to be more competitive than antibioticsensitive strains, while those resistant to penicillin could not compete even with antibiotic-sensitive strains.

scholarly journals Bacteremia in Ibn Al-Baladi hospital in Baghdad; Incidence etiology and antibiotic resistance of pathogens

2009 ◽  
Vol 6 (3) ◽  
pp. 549-552
Author(s):  
Baghdad Science Journal
Keyword(s):  
Drug Resistance ◽  
Antibiotic Resistance ◽  
High Resistance ◽  
Antimicrobial Agents ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
Gram Negative ◽  
Antimicrobial Sensitivity ◽  
Sensitivity Tests ◽  
Gram Negative Organisms

60 cases of Bacteremia were documented at Ibn Al-Baladi hospital during 6 months (1-1-2002 to 1-7-2002), with an incidence of 5.2 were gram-negative organisms and most common one was Salmonella and Klebsiella. Incidence was significantly higher in male than female .Antimicrobial sensitivity tests revealed that isolated bacteria are with multiple drug resistance to commonly used antimicrobial agents. Salmonella showed high resistance to cephaloxin, co-trimoxazole and amoxicillin and also Klebsiella showed resistance to cephaloxin and amoxicillin.

scholarly journals Multiple drug resistance in Candida albicans.

1995 ◽  
Vol 42 (4) ◽  
pp. 497-504 ◽  
Author(s):  
R Prasad ◽  
S K Murthy ◽  
V Gupta ◽  
R Prasad
Keyword(s):  
Drug Resistance ◽  
Multidrug Resistance ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
Pleiotropic Drug Resistance ◽  
Multidrug Resistance Gene ◽  
Hydrophobic Region ◽  
Membrane Pump ◽  
Collateral Sensitivity ◽  
Sensitivity Pattern

By functional complementation of a PDR 5 (pleiotropic drug resistance) null mutant of S. cerevisiae, we have recently cloned and sequenced a multidrug resistance gene CDR 1 (Candida Drug Resistance). Transformation by CDR 1 of a PDR 5 disrupted host hypersensitive to cycloheximide and chloramphenicol resulted in resistance to these as well as other unrelated drugs. The nucleotide sequence of CDR 1 revealed that, like PDR 5, it encodes a putative membrane pump belonging to the ABC superfamily. CDR 1 encodes a protein of 169.9 kDa whose predicted structural organisation is characterised by two homologous halves, each comprising a hydrophobic region, with a set of six transmembrane stretches, preceded by a hydrophilic binding fold. We now have evidence to suggest that there are several PDR homologues present in C. albicans which display multidrug resistance and a collateral sensitivity pattern different from PDR 5 and CDR 1. The functions of such genes and their products in the overall physiology of C. albicans is not yet established.

scholarly journals Multiple-drug-resistance phenomenon in the yeast Saccharomyces cerevisiae: involvement of two hexose transporters.

1997 ◽  
Vol 17 (9) ◽  
pp. 5453-5460 ◽  
Author(s):  
A Nourani ◽  
M Wesolowski-Louvel ◽  
T Delaveau ◽  
C Jacq ◽  
A Delahodde
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Drug Resistance ◽  
Multidrug Resistance ◽  
Abc Transporters ◽  
Multiple Drug Resistance ◽  
Kluyveromyces Lactis ◽  
Major Facilitator Superfamily ◽  
Multiple Drug ◽  
Yeast Saccharomyces Cerevisiae ◽  
Hexose Transporters

In the yeast Saccharomyces cerevisiae, multidrug resistance to unrelated chemicals can result from overexpression of ATP-binding cassette (ABC) transporters such as Pdr5p, Snq2p, and Yor1p. Expression of these genes is under the control of two homologous zinc finger-containing transcription regulators, Pdr1p and Pdr3p. Here, we describe the isolation, by an in vivo screen, of two new Pdr1p-Pdr3p target genes: HXT11 and HXT9. HXT11 and HXT9, encoding nearly identical proteins, have a high degree of identity to monosaccharide transporters of the major facilitator superfamily (MFS). In this study, we show that the HXT11 product, which allows glucose uptake in a glucose permease mutant (rag1) strain of Kluyveromyces lactis, is also involved in the pleiotropic drug resistance process. Loss of HXT11 and/or HXT9 confers cycloheximide, sulfomethuron methyl, and 4-NQO (4-nitroquinoline-N-oxide) resistance. Conversely, HXT11 overexpression increases sensitivity to these drugs in the wild-type strain, an effect which is more pronounced in a strain having both PDR1 and PDR3 deleted. These data show that the two putative hexose transporters Hxt11p and Hxt9p are transcriptionally regulated by the transcription factors Pdr1p and Pdr3p, which are known to regulate the production of ABC transporters required for drug resistance in yeast. We thus demonstrate the existence of genetic interactions between genes coding for two classes of transporters (ABC and MFS) to control the multidrug resistance process.

Sign in / Sign up

Export Citation Format

Share Document