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.

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 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.

scholarly journals Impact of unhygienic conditions during slaughtering and processing on spread of antibiotic resistant Escherichia coli from poultry

2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Mamoona Amir ◽  
Muhammad Riaz ◽  
Yung-Fu Chang ◽  
Saeed Akhtar ◽  
Sang Ho Yoo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Resistance Genes ◽  
Tap Water ◽  
Tetracycline Resistance ◽  
Health Concern ◽  
Cross Contamination ◽  
Broiler Meat ◽  
E Coli ◽  
Tetracycline Resistance Genes

Antibiotic resistance in Escherichia coli is a global health concern. We studied all possible routes of cross contamination of broiler meat with resistant E. coli from broiler feces at poultry shops. Various sample categories namely poultry feces, meat (n=225 for each), slaughterer hands, consumer hands, slaughterer knife, canister, tap water, carcass, feed and drinking water (n=50 for each) were collected from local poultry processing market. Samples were screened for prevalence of E. coli, resistance of isolates against ten antibiotics and presence of tetracycline- resistance genes in the isolates. Fecal samples had greatest colony count (4.1×104 CFU/g) as compared to meat (1.9×104 CFU/g) samples. Samples of consumer hands (6%) and tap water (12%) had less prevalence percentages of E. coli as compared to slaughterer hands (92%) and drinking water of broiler (86%). Isolates of eight sample categories had high resistant rate (≥90%) against oxytetracycline. On average, about 94% of the isolates from various sample categories possessed multidrug-resistance (MDR). Tetracycline-resistance genes (tetA and tetB) were identified in all sample categories except isolates of consumer hands and tap water. The distribution of tetracycline-resistance genes was significantly greater in fecal isolates (42%) than meat isolates (25%). The study depicted the spread of resistant E. coli in broiler meat through all studied routes of contamination of slaughtering periphery. This problem can be mitigated by strict monitoring of antibiotics use at poultry farms, prevention of cross contamination by adopting hygienic slaughter and vigorously screening the market meat for resistant E. coli.

scholarly journals Manure Compost Is a Potential Source of Tetracycline-Resistant Escherichia coli and Tetracycline Resistance Genes in Japanese Farms

Antibiotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 76 ◽  
Author(s):  
Nobuki Yoshizawa ◽  
Masaru Usui ◽  
Akira Fukuda ◽  
Tetsuo Asai ◽  
Hidetoshi Higuchi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Tetracycline Resistance ◽  
Resistant Bacteria ◽  
E Coli ◽  
Tetracycline Resistance Genes ◽  
Manure Compost ◽  
Potential Source ◽  
Antimicrobial Resistance Genes ◽  
Route Of Transmission

Manure compost has been thought of as a potential important route of transmission of antimicrobial-resistant bacteria (ARB) and antimicrobial resistance genes (ARGs) from livestock to humans. To clarify the abundance of ARB and ARGs, ARB and ARGs were quantitatively determined in tetracycline-resistant Escherichia coli (harboring the tetA gene)-spiked feces in simulated composts. In the simulated composts, the concentration of spiked E. coli decreased below the detection limit at day 7. The tetA gene remained in manure compost for 20 days, although the levels of the gene decreased. Next, to clarify the field conditions of manure compost in Japan, the quantities of tetracycline-resistant bacteria, tetracycline resistance genes, and residual tetracyclines were determined using field-manure-matured composts in livestock farms. Tetracycline-resistant bacteria were detected in 54.5% of tested matured compost (6/11 farms). The copy number of the tetA gene and the concentrations of residual tetracyclines in field manure compost were significantly correlated. These results suggest that the use of antimicrobials in livestock constitutes a selective pressure, not only in livestock feces but also in manure compost. The appropriate use of antimicrobials in livestock and treatment of manure compost are important for avoiding the spread of ARB and ARGs.

Characterization of tetracycline resistance genes in Escherichia coli isolated from feedlot cattle administered therapeutic or subtherapeutic levels of tetracycline

2013 ◽  
Vol 59 (4) ◽  
pp. 287-290 ◽  
Author(s):  
T.W. Alexander ◽  
X. Jin ◽  
Q. Li ◽  
S. Cook ◽  
T.A. McAllister
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Tetracycline Resistance ◽  
Feedlot Cattle ◽  
E Coli ◽  
Treatment Regimes ◽  
Tetracycline Resistance Genes ◽  
Polymerase Chain ◽  
Selection Of

The effect of administering feedlot cattle subtherapeutic levels of chlortetracycline (CT) or CT and therapeutic levels of oxytetracycline (CT-OX) on resistance genotypes in Escherichia coli was investigated. Detection of genes tet(A), tet(B), and tet(C) encoded by tetracycline-resistant isolates (CT, N = 77; CT-OX, N = 99) was performed by multiplex polymerase chain reaction (PCR). Prevalence of tet(A) was similar in isolates across treatment regimes; however, prevalence of tet(B) was lower (18% versus 34%; P < 0.05) and tet(C) was higher (46% versus 28%; P < 0.05) in CT isolates compared with CT-OX isolates. To further characterize selection of resistance genotypes in E. coli, a group of intermediately tetracycline-resistant E. coli (N = 48) was analyzed. The tet(C) gene was present in 92% of these isolates. Copies of tet(C) transcripts, analyzed by real-time PCR, indicated that upregulation did not occur in tetracycline-resistant isolates when compared with intermediately resistant isolates. The minimum inhibitory concentrations of tetracycline, chlortetracycline, and oxytetracycline were also tested on isolates with different resistance genes. The minimum inhibitory concentration was dependent on the tetracycline analogue and the nature of encoded resistance. These data indicate that tetracycline analogues should not be used interchangeably to evaluate resistance and that prevalence of resistance genes in E. coli can vary according to the tetracycline analogue administered to cattle.

Commensal Escherichia coli of healthy humans: a reservoir for antibiotic-resistance determinants

2010 ◽  
Vol 59 (11) ◽  
pp. 1331-1339 ◽  
Author(s):  
Jannine K. Bailey ◽  
Jeremy L. Pinyon ◽  
Sashindran Anantham ◽  
Ruth M. Hall
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Resistant Strain ◽  
Healthy Adults ◽  
Susceptible Strain ◽  
E Coli ◽  
Resistance Determinants ◽  
Healthy Humans ◽  
Depth Analysis

This study examined in detail the population structure of Escherichia coli from healthy adults with respect to the prevalence of antibiotic resistance and specific resistance determinants. E. coli isolated from the faeces of 20 healthy adults not recently exposed to antibiotics was tested for resistance to ten antibiotics and for carriage of integrons and resistance determinants using PCR. Strain diversity was assessed using biochemical and molecular criteria. E. coli was present in 19 subjects at levels ranging from 2.0×104 to 1.7×108 c.f.u. (g faeces)−1. Strains resistant to one to six antibiotics were found at high levels (>30 %) in only ten individuals, but at significant levels (>0.5 %) in 14. Resistant isolates with the same phenotype from the same individual were indistinguishable, but more than one susceptible strain was sometimes found. Overall, individuals harboured one to four E. coli strains, although in 17 samples one strain was dominant (>70 % of isolates). Eighteen strains resistant to ampicillin, sulfamethoxazole, tetracycline and trimethoprim in 15 different combinations were observed. One resistant strain was carried by two unrelated individuals and a susceptible strain was shared by two cohabiting subjects. Two minority strains were derivatives of a more abundant resistant strain in the same sample, showing that continuous evolution is occurring in vivo. The trimethoprim-resistance genes dfrA1, dfrA5, dfrA7, dfrA12 or dfrA17 were in cassettes in a class 1 or class 2 integron. Ampicillin resistance was conferred by the bla TEM gene, sulfamethoxazole resistance by sul1, sul2 or sul3 and tetracycline resistance by tetA(A) or tetA(B). Chloramphenicol resistance (cmlA1 gene) was detected only once. Phylogenetic groups A and B2 were more common than B1 and D. Commensal E. coli of healthy humans represent an important reservoir for numerous antibiotic-resistance genes in many combinations. However, measuring the true extent of resistance carriage in commensal E. coli requires in-depth analysis.

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