Tissue Distribution and Chemical Induction of Multiple Drug Resistance Genes in Rats

2002 ◽  
Vol 30 (7) ◽  
pp. 838-844 ◽  
Author(s):  
James M. Brady ◽  
Nathan J. Cherrington ◽  
Dylan P. Hartley ◽  
Susan C. Buist ◽  
Ning Li ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Tissue Distribution ◽  
Resistance Genes ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
Chemical Induction

scholarly journals Mechanisms of bacterial multiresistance to antibiotics

2018 ◽  
Vol 16 (3) ◽  
pp. 4-17 ◽  
Author(s):  
Olga M. Zemlyanko ◽  
Tatyana M. Rogoza ◽  
Galina A. Zhouravleva
Keyword(s):  
Drug Resistance ◽  
Clinical Practice ◽  
Resistance Genes ◽  
Horizontal Transfer ◽  
Pathogenic Bacteria ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
Bacterial Strains ◽  
Current Review

Multiple drug resistance (MDR) to widening range of antibiotics emerging in increasing variety of pathogenic bacteria is a serious threat to the health of mankind nowadays. This is partially due to an uncontrolled usage of antibiotics not only in clinical practice, but also in various branches of agriculture. MDR is affected by two mechanisms: (1) accumulation of resistance genes as a result of intensive selection caused by antibiotics, and (2) active horizontal transfer of resistance genes. To unveil the reasons of bacterial multiresistance to antibiotics, it is necessary to understand the mechanisms of antibiotics action as well as the ways how either resistance to certain antibiotics emerge or resistance genes accumulate and transfer among bacterial strains. Current review is devoted to all these problems.

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.

scholarly journals Ciclopirox Olamine Treatment Affects the Expression Pattern of Candida albicans Genes Encoding Virulence Factors, Iron Metabolism Proteins, and Drug Resistance Factors

2003 ◽  
Vol 47 (6) ◽  
pp. 1805-1817 ◽  
Author(s):  
Markus Niewerth ◽  
Donika Kunze ◽  
Michael Seibold ◽  
Martin Schaller ◽  
Hans Christian Korting ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Candida Albicans ◽  
Resistance Genes ◽  
Mode Of Action ◽  
Multiple Drug Resistance ◽  
Expression Patterns ◽  
Multiple Drug ◽  
Ciclopirox Olamine ◽  
Genes Encoding ◽  
In Cells

ABSTRACT The hydroxypyridone ciclopirox olamine belongs to the antimycotic drugs used for the treatment of superficial mycoses. In contrast to the azoles and other antimycotic drugs, its specific mode of action is only poorly understood. To investigate the mode of action of ciclopirox olamine on fungal viability, pathogenicity, and drug resistance, we examined the expression patterns of 47 Candida albicans genes in cells grown in the presence of a subinhibitory concentration (0.6 μg/ml) of ciclopirox olamine by reverse transcription-PCR. In addition, we used suppression-subtractive hybridization to further identify genes that are up-regulated in the presence of ciclopirox olamine. The expression of essential genes such as ACT1 was not significantly modified in cells exposed to ciclopirox olamine. Most putative and known virulence genes such as genes encoding secreted proteinases or lipases had no or only moderately reduced expression levels. In contrast, exposure of cells to ciclopirox olamine led to a distinct up- or down-regulation of genes encoding iron permeases or transporters (FTR1, FTR2, FTH1), a copper permease (CCC2), an iron reductase (CFL1), and a siderophore transporter (SIT1); these effects resembled those found under iron-limited conditions. Addition of FeCl3 to ciclopirox olamine-treated cells reversed the effect of the drug. Addition of the iron chelator bipyridine to the growth medium induced similar patterns of expression of distinct iron-regulated genes (FTR1, FTR2). While serum-induced yeast-to-hyphal phase transition of C. albicans was not affected in ciclopirox olamine-treated cells in the presence of subinhibitory conditions, a dramatic increase in sensitivity to oxidative stress was noted, which may indicate the reduced activities of iron-containing gene products responsible for detoxification. Although the Candida drug resistance genes CDR1 and CDR2 were up-regulated, no change in resistance or increased tolerance could be observed even after an incubation period of 6 months. This was in contrast to control experiments with fluconazole, in which the MICs for cells incubated with this drug had noticeably increased after 2 months. These data support the view that the antifungal activity of ciclopirox olamine may at least be partially caused by iron limitation. Furthermore, neither the expression of certain multiple-drug resistance genes nor other resistance mechanisms caused C. albicans resistance to this drug even after long-term exposure.

scholarly journals Overexpression of Multiple Drug Resistance Genes in Endothelial Cells from Patients with Refractory Epilepsy

Epilepsia ◽  
2001 ◽  
Vol 42 (12) ◽  
pp. 1501-1506 ◽  
Author(s):  
Stephen M. Dombrowski ◽  
Shailesh Y. Desai ◽  
Matteo Marroni ◽  
Luca Cucullo ◽  
Kris Goodrich ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Endothelial Cells ◽  
Resistance Genes ◽  
Refractory Epilepsy ◽  
Multiple Drug Resistance ◽  
Multiple Drug

scholarly journals Prevalence of virulence and antimicrobial resistance genes in Salmonella spp. isolated from commercial chickens and human clinical isolates from South Africa and Brazil

2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Oliver T. Zishiri ◽  
Nelisiwe Mkhize ◽  
Samson Mukaratirwa
Keyword(s):  
Drug Resistance ◽  
Antimicrobial Resistance ◽  
South African ◽  
Resistance Genes ◽  
Broiler Chickens ◽  
Antimicrobial Agents ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
Poultry Production ◽  
Antimicrobial Resistance Genes

Salmonellosis is a significant public health concern around the world. The injudicious use of antimicrobial agents in poultry production for treatment, growth promotion and prophylaxis has resulted in the emergence of drug resistant strains of Salmonella. The current study was conducted to investigate the prevalence of virulence and antimicrobial resistance genes from Salmonella isolated from South African and Brazilian broiler chickens as well as human clinical isolates. Out of a total of 200 chicken samples that were collected from South Africa 102 (51%) tested positive for Salmonella using the InvA gene. Of the overall 146 Salmonella positive samples that were screened for the iroB gene most of them were confirmed to be Salmonella enterica with the following prevalence rates: 85% of human clinical samples, 68.6% of South African chicken isolates and 70.8% of Brazilian chicken samples. All Salmonella isolates obtained were subjected to antimicrobial susceptibility testing with 10 antibiotics. Salmonella isolates from South African chickens exhibited resistance to almost all antimicrobial agents used, such as tetracycline (93%), trimethoprim-sulfamthoxazole (84%), trimethoprim (78.4%), kanamycin (74%), gentamicin (48%), ampicillin (47%), amoxicillin (31%), chloramphenicol (31%), erythromycin (18%) and streptomycin (12%). All samples were further subjected to PCR in order to screen some common antimicrobial and virulence genes of interest namely spiC, pipD, misL, orfL, pse-1, tet A, tet B, ant (3")-la, sul 1 and sul. All Salmonella positive isolates exhibited resistance to at least one antimicrobial agent; however, antimicrobial resistance patterns demonstrated that multiple drug resistance was prevalent. The findings provide evidence that broiler chickens are colonised by pathogenic Salmonella harbouring antimicrobial resistance genes. Therefore, it is evident that there is a need for prudent use of antimicrobial agents in poultry production systems in order to mitigate the proliferation of multiple drug resistance across species.Keywords: Salmonella; antimicrobial resistance; chicken; human; susceptibility; virulence gene

scholarly journals Emergence of Staphylococcus aureus Carrying Multiple Drug Resistance Genes on a Plasmid Encoding Exfoliative Toxin B

2013 ◽  
Vol 57 (12) ◽  
pp. 6131-6140 ◽  
Author(s):  
Junzo Hisatsune ◽  
Hideki Hirakawa ◽  
Takayuki Yamaguchi ◽  
Yasuyuki Fudaba ◽  
Kenshiro Oshima ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Drug Resistance ◽  
Resistance Genes ◽  
Multiple Drug Resistance ◽  
Antimicrobial Treatment ◽  
Multiple Drug ◽  
Toxin Gene ◽  
Toxin B ◽  
Content Type ◽  
Exfoliative Toxin

ABSTRACTWe report the complete nucleotide sequence and analysis of pETBTY825, aStaphylococcus aureusTY825 plasmid encoding exfoliative toxin B (ETB).S. aureusTY825 is a clinical isolate obtained from an impetigo patient in 2002. The size of pETBTY825, 60.6 kbp, was unexpectedly larger than that of the archetype pETBTY4(∼30 kbp). Genomic comparison of the plasmids shows that pETBTY825has the archetype pETBTY4as the backbone and has a single large extra DNA region of 22.4 kbp. The extra DNA region contains genes for resistance to aminoglycoside [aac(6′)/aph(2″)], macrolide (msrA), and penicillin (blaZ). A plasmid deletion experiment indicated that these three resistance elements were functionally active. We retrospectively examined the resistance profile of the clinical ETB-producingS. aureusstrains isolated in 1977 to 2007 using a MIC determination with gentamicin (GM), arbekacin (ABK), and erythromycin (EM) and by PCR analyses foraac(6′)/aph(2″) andmsrAusing purified plasmid preparations. The ETB-producingS. aureusstrains began to display high resistance to GM, which was parallel with the detection ofaac(6′)/aph(2″) andmecA, after 1990. Conversely, there was no significant change in the ABK MIC during the testing period, although it had a tendency to slightly increase. After 2001, isolates resistant to EM significantly increased; however,msrAwas hardly detected in ETB-producingS. aureusstrains, and only five isolates were positive for bothaac(6′)/aph(2″) andmsrA. In this study, we report the emergence of a fusion plasmid carrying the toxin geneetband drug resistance genes. Prevalence of the pETBTY825carrier may further increase the clinical threat, since ETB-producingS. aureusis closely related to more severe impetigo or staphylococcal scalded-skin syndrome (SSSS), which requires a general antimicrobial treatment.

Sign in / Sign up

Export Citation Format

Share Document