scholarly journals Microarray Analysis of Escherichia coli Strains from Interstitial Beach Waters of Lake Huron (Canada)

2007 ◽  
Vol 73 (23) ◽  
pp. 7757-7758 ◽  
Author(s):  
T. Kon ◽  
S. C. Weir ◽  
J. T. Trevors ◽  
H. Lee ◽  
J. Champagne ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Microarray ◽  
Interstitial Water ◽  
Tetracycline Resistance ◽  
Lake Huron ◽  
Tetracycline Resistance Genes ◽  
Microarray Analyses ◽  
Repetitive Extragenic Palindromic Pcr ◽  
Beach Water ◽  
Repetitive Extragenic Palindromic

ABSTRACT DNA microarray analyses revealed that clusters of repetitive extragenic palindromic PCR-related Escherichia coli isolates were isogenic only within interstitial Lake Huron beach water samples and not in surrounding waters. This suggested that adaptation and growth occurred within the interstitial water sites tested. All isolates were nonpathogenic, and three lake isolates possessed tetracycline resistance genes.

Detection of efflux pump genes in multiresistant Acinetobacter baumannii ST2 in Iran

2021 ◽  
Author(s):  
Zahra Meshkat ◽  
Himen Salimizand ◽  
Yousef Amini ◽  
Davood Mansury ◽  
Abolfazl Rafati Zomorodi ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Efflux Pump ◽  
Tetracycline Resistance ◽  
Genomic Diversity ◽  
Expression Level ◽  
Tetracycline Resistance Genes ◽  
Microdilution Method ◽  
Relationship Of ◽  
Repetitive Extragenic Palindromic Pcr

AbstractAcinetobacter baumannii, as a nosocomial pathogen has become a worldwide concern in recent years. In the current study, the resistance to tetracyclines and colistin were assessed in the isolates from different provinces of Iran.During the timeline of this study, a number of 270 isolates of A. baumannii were collected from tracheal aspirates, wounds, urine and blood cultures. The minimum inhibitory concentration (MIC) for tetracycline, doxycycline, minocycline, tigecycline and colistin were evaluated. Tetracycline resistance genes were assessed by PCR. The mean expression level of adeB, adeJ and adeG were assessed using semi quantitative Real-Time PCR. The clonal relationship of the isolates was evaluated by the repetitive extragenic palindromic PCR (REP-PCR), International Clonal (IC) Lineage Multiplex PCR and multilocus sequence typing (MLST) (Pasteur scheme) methods.The MIC by microdilution method showed that 87.5, 51.4, 28, 0.74 and 0% of the isolates were resistant to tetracycline, doxycycline, minocycline, tigecycline and colistin respectively. The prevalence of tetracycline resistance genes was 99.2, 99.2, 98, 86.7, 10, 3.33, 0.37, 0% for adeB, adeJ, adeG, tetB, tetA(39), tetA, tetM and tetH in tetracycline-resistant isolates. Moreover, the expression level of adeB, adeJ, adeG genes in tigecycline-nonsusceptible A. baumannii (TNAB) strain was higher compared to the tigecycline-susceptible A. baumannii (TSAB). A broad genomic diversity was revealed, but ST2 was the most prevalent ST. Our results indicated that tetracycline resistance in Iran is mediated by resistance-nodulation-cell division (RND) and tetB efflux pumps.

scholarly journals Prevalence of Antimicrobial Resistance and Transfer of Tetracycline Resistance Genes in Escherichia coli Isolates from Beef Cattle

2015 ◽  
Vol 81 (16) ◽  
pp. 5560-5566 ◽  
Author(s):  
Seung Won Shin ◽  
Min Kyoung Shin ◽  
Myunghwan Jung ◽  
Kuastros Mekonnen Belaynehe ◽  
Han Sang Yoo
Keyword(s):  
Escherichia Coli ◽  
South Korea ◽  
Beef Cattle ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Tetracycline Resistance ◽  
Tetracycline Resistance Gene ◽  
Content Type ◽  
E Coli ◽  
Tetracycline Resistance Genes

ABSTRACTThe aim of this study was to investigate the prevalence and transferability of resistance in tetracycline-resistantEscherichia coliisolates recovered from beef cattle in South Korea. A total of 155E. coliisolates were collected from feces in South Korea, and 146 were confirmed to be resistant to tetracycline. The tetracycline resistance genetet(A) (46.5%) was the most prevalent, followed bytet(B) (45.1%) andtet(C) (5.8%). Strains carryingtet(A) plustet(B) andtet(B) plustet(C) were detected in two isolates each. In terms of phylogenetic grouping, 101 (65.2%) isolates were classified as phylogenetic group B1, followed in decreasing order by D (17.4%), A (14.2%), and B2 (3.2%). Ninety-one (62.3%) isolates were determined to be multidrug resistant by the disk diffusion method. MIC testing using the principal tetracyclines, namely, tetracycline, chlortetracycline, oxytetracycline, doxycycline, and minocycline, revealed that isolates carryingtet(B) had higher MIC values than isolates carryingtet(A). Conjugation assays showed that 121 (82.9%) isolates could transfer a tetracycline resistance gene to a recipient via the IncFIB replicon (65.1%). This study suggests that the high prevalence of tetracycline-resistantE. coliisolates in beef cattle is due to the transferability of tetracycline resistance genes betweenE. colipopulations which have survived the selective pressure caused by the use of antimicrobial agents.

scholarly journals Identifying Host Sources of Fecal Pollution: Diversity of Escherichia coli in Confined Dairy and Swine Production Systems

2005 ◽  
Vol 71 (10) ◽  
pp. 5992-5998 ◽  
Author(s):  
Zexun Lu ◽  
David Lapen ◽  
Andrew Scott ◽  
Angela Dang ◽  
Edward Topp
Keyword(s):  
Escherichia Coli ◽  
Dairy Farm ◽  
Sampling Strategy ◽  
Farming Systems ◽  
Microbial Source Tracking ◽  
Fecal Pollution ◽  
Source Tracking ◽  
E Coli ◽  
Repetitive Extragenic Palindromic Pcr ◽  
Repetitive Extragenic Palindromic

ABSTRACT Repetitive extragenic palindromic PCR fingerprinting of Escherichia coli is one microbial source tracking approach for identifying the host source origin of fecal pollution in aquatic systems. The construction of robust known-source libraries is expensive and requires an informed sampling strategy. In many types of farming systems, waste is stored for several months before being released into the environment. In this study we analyzed, by means of repetitive extragenic palindromic PCR using the enterobacterial repetitive intergenic consensus primers and comparative analysis using the Bionumerics software, collections of E. coli obtained from a dairy farm and from a swine farm, both of which stored their waste as a slurry in holding tanks. In all fecal samples, obtained from either barns or holding tanks, the diversity of the E. coli populations was underrepresented by collections of 500 isolates. In both the dairy and the swine farms, the diversity of the E. coli community was greater in the manure holding tank than in the barn, when they were sampled on the same date. In both farms, a comparison of stored manure samples collected several months apart suggested that the community composition changed substantially in terms of the detected number, absolute identity, and relative abundance of genotypes. Comparison of E. coli populations obtained from 10 different locations in either holding tank suggested that spatial variability in the E. coli community should be accounted for when sampling. Overall, the diversity in E. coli populations in manure slurry storage facilities is significant and likely is problematic with respect to library construction for microbial source tracking applications.

scholarly journals Occurrence of Tetracycline Resistance Genes among Escherichia coli Isolates from the Phase 3 Clinical Trials for Tigecycline

2007 ◽  
Vol 51 (9) ◽  
pp. 3205-3211 ◽  
Author(s):  
Margareta Tuckman ◽  
Peter J. Petersen ◽  
Anita Y. M. Howe ◽  
Mark Orlowski ◽  
Stanley Mullen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Trials ◽  
Tetracycline Resistance ◽  
Phase 3 ◽  
E Coli ◽  
Tetracycline Resistance Genes ◽  
Resistance Determinants ◽  
Resistant Strains ◽  
A Current ◽  
Antibacterial Spectrum

ABSTRACT Tigecycline, a member of the glycylcycline class of antibiotics, was designed to maintain the antibacterial spectrum of the tetracyclines while overcoming the classic mechanisms of tetracycline resistance. The current study was designed to monitor the prevalence of the tet(A), tet(B), tet(C), tet(D), tet(E), and tet(M) resistance determinants in Escherichia coli isolates collected during the worldwide tigecycline phase 3 clinical trials. A subset of strains were also screened for the tet(G), tet(K), tet(L), and tet(Y) genes. Of the 1,680 E. coli clinical isolates screened for resistance to classical tetracyclines, 405 (24%) were minocycline resistant (MIC ≥ 8 μg/ml) and 248 (15%) were tetracycline resistant (MIC ≥ 8 μg/ml) but susceptible to minocycline (MIC ≤ 4 μg/ml). A total of 452 tetracycline-resistant, nonduplicate isolates were positive by PCR for at least one of the six tetracycline resistance determinants examined. Over half of the isolates encoding a single determinant were positive for tet(A) (26%) or tet(B) (32%) with tet(C), tet(D), tet(E), and tet(M), collectively, found in 4% of isolates. Approximately 33% of the isolates were positive for more than one resistance determinant, with the tet(B) plus tet(E) combination the most highly represented, found in 11% of isolates. The susceptibilities of the tetracycline-resistant strains to tigecycline (MIC90, 0.5 μg/ml), regardless of the encoded tet determinant(s), were comparable to the tigecycline susceptibility of tetracycline-susceptible strains (MIC90, 0.5 μg/ml). The results provide a current (2002 to 2006) picture of the distribution of common tetracycline resistance determinants encoded in a globally sourced collection of clinical E. coli strains.

Prevalence of tetracycline resistance genes and identification of tet(M) in clinical isolates of Escherichia coli from sick ducks in China

2013 ◽  
Vol 62 (6) ◽  
pp. 851-858 ◽  
Author(s):  
Gong-Zheng Hu ◽  
Yu-Shan Pan ◽  
Hua Wu ◽  
Han Hu ◽  
Rui Xu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Promoter Region ◽  
Tetracycline Resistance ◽  
Resistance Rate ◽  
Clinical Isolates ◽  
Animal Origin ◽  
Broth Microdilution ◽  
M Gene ◽  
Tetracycline Resistance Genes

Tetracycline resistance is one of the most frequently encountered resistance properties in bacteria of animal origin. The aim of the present study was to investigate the prevalence and diversity of tetracycline resistance (tet) genes among Escherichia coli clinical isolates from diseased ducks in China and to report the identification and sequencing of the tet(M) gene. The susceptibility of 85 Escherichia coli strains to tetracyclines was determined by broth microdilution, and the presence of tet genes was investigated by multiplex PCR. All of the 85 isolates were fully resistant to both oxytetracycline and tetracycline, and 76.5 % were resistant to doxycycline. Seventy-seven of the isolates (90.6 %) encoded multiple tet genes, with 17.6, 38.8 and 34.1 % encoding two, three and four tet genes, respectively, and only 7.1 % encoded a single tet(A) gene. The MICs of oxytetracycline and tetracycline for all isolates ranged from 16 to ≥128 µg ml−1 with a MIC90 of >128 µg ml−1, regardless of the type or number of tet genes encoded. Isolates containing tet(M) commonly had more than one tet gene per strain. The doxycycline resistance rate in the tet(M)-positive isolates was significantly higher than in the tet(M)-negative isolates (P<0.05). A full-length tet(M) gene, including the promoter region, was obtained by PCR in seven of the 41 tet(M)-positive isolates and was sequenced and cloned. The cloned tet(M) gene conferred resistance to tetracyclines in the recombinant Escherichia coli host strain. These results revealed that, in these isolates, the prevalence of multiple tet genes was strikingly high and that tet(M) played a role in doxycycline resistance.

scholarly journals Frequency and Distribution of Tetracycline Resistance Genes in Genetically Diverse, Nonselected, and Nonclinical Escherichia coli Strains Isolated from Diverse Human and Animal Sources

2004 ◽  
Vol 70 (4) ◽  
pp. 2503-2507 ◽  
Author(s):  
Andrew Bryan ◽  
Nir Shapir ◽  
Michael J. Sadowsky
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Natural Populations ◽  
Tetracycline Resistance ◽  
First Report ◽  
E Coli ◽  
Tetracycline Resistance Genes ◽  
Resistance Determinants

ABSTRACT Nonselected and natural populations of Escherichia coli from 12 animal sources and humans were examined for the presence and types of 14 tetracycline resistance determinants. Of 1,263 unique E. coli isolates from humans, pigs, chickens, turkeys, sheep, cows, goats, cats, dogs, horses, geese, ducks, and deer, 31% were highly resistant to tetracycline. More than 78, 47, and 41% of the E. coli isolates from pigs, chickens, and turkeys were resistant or highly resistant to tetracycline, respectively. Tetracycline MICs for 61, 29, and 29% of E. coli isolates from pig, chickens, and turkeys, respectively, were ≥233 μg/ml. Muliplex PCR analyses indicated that 97% of these strains contained at least 1 of 14 tetracycline resistance genes [tetA, tetB, tetC, tetD, tetE, tetG, tetK, tetL, tetM, tetO, tetS, tetA(P), tetQ, and tetX] examined. While the most common genes found in these isolates were tetB (63%) and tetA (35%), tetC, tetD, and tetM were also found. E. coli isolates from pigs and chickens were the only strains to have tetM. To our knowledge, this represents the first report of tetM in E. coli.

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