Propensity of activated sludge to amplify or attenuate tetracycline resistance genes and tetracycline resistant bacteria: A mathematical modeling approach

Chemosphere ◽  
2010 ◽  
Vol 78 (9) ◽  
pp. 1071-1077 ◽  
Author(s):  
Sungpyo Kim ◽  
Hongkeun Park ◽  
Kartik Chandran
Keyword(s):  
Mathematical Modeling ◽  
Activated Sludge ◽  
Resistance Genes ◽  
Tetracycline Resistance ◽  
Resistant Bacteria ◽  
Tetracycline Resistance Genes ◽  
Modeling Approach

scholarly journals Prevalence of Tetracycline Resistance Genes in Oral Bacteria

2003 ◽  
Vol 47 (3) ◽  
pp. 878-882 ◽  
Author(s):  
A. Villedieu ◽  
M. L. Diaz-Torres ◽  
N. Hunt ◽  
R. McNab ◽  
D. A. Spratt ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Tetracycline Resistance ◽  
Oral Bacteria ◽  
Healthy Adults ◽  
Resistant Bacteria ◽  
First Report ◽  
Tetracycline Resistance Genes ◽  
Oral Microflora ◽  
Genes Encoding ◽  
Ribosomal Protection Protein

ABSTRACT Tetracycline is a broad-spectrum antibiotic used in humans, animals, and aquaculture; therefore, many bacteria from different ecosystems are exposed to this antibiotic. In order to determine the genetic basis for resistance to tetracycline in bacteria from the oral cavity, saliva and dental plaque samples were obtained from 20 healthy adults who had not taken antibiotics during the previous 3 months. The samples were screened for the presence of bacteria resistant to tetracycline, and the tetracycline resistance genes in these isolates were identified by multiplex PCR and DNA sequencing. Tetracycline-resistant bacteria constituted an average of 11% of the total cultivable oral microflora. A representative 105 tetracycline-resistant isolates from the 20 samples were investigated; most of the isolates carried tetracycline resistance genes encoding a ribosomal protection protein. The most common tet gene identified was tet(M), which was found in 79% of all the isolates. The second most common gene identified was tet(W), which was found in 21% of all the isolates, followed by tet(O) and tet(Q) (10.5 and 9.5% of the isolates, respectively) and then tet(S) (2.8% of the isolates). Tetracycline resistance genes encoding an efflux protein were detected in 4.8% of all the tetracycline-resistant isolates; 2.8% of the isolates had tet(L) and 1% carried tet(A) and tet(K) each. The results have shown that a variety of tetracycline resistance genes are present in the oral microflora of healthy adults. This is the first report of tet(W) in oral bacteria and the first report to show that tet(O), tet(Q), tet(A), and tet(S) can be found in some oral species.

Diversity of tet resistance genes in tetracycline-resistant bacteria isolated from a swine lagoon with low antibiotic impact

2007 ◽  
Vol 53 (12) ◽  
pp. 1307-1315 ◽  
Author(s):  
John J Macauley ◽  
Craig D. Adams ◽  
Melanie R. Mormile
Keyword(s):  
Resistance Genes ◽  
Tetracycline Resistance ◽  
Antibiotic Use ◽  
Resistant Bacteria ◽  
Concentrated Animal Feeding Operations ◽  
Animal Feeding Operations ◽  
Tetracycline Resistance Genes ◽  
Animal Feeding ◽  
Ribosomal Protection Protein ◽  
Ribosomal Protection

Tetracycline resistance has been extensively studied and shown to be widespread. A number of previous studies have clearly demonstrated that a variety of tetracycline resistance genes are present in swine fecal material, treatment lagoons, and the environments surrounding concentrated animal feeding operations (CAFOs). The diversity of tetracycline resistance within a swine lagoon located at a CAFO that used only bacitricin methylene disalicylate as an antibiotic was evaluated by screening 85 tetracycline-resistant isolates for the presence of 18 different genes by performing PCR with primers that target tetracycline efflux genes of Gram-negative bacteria and ribosomal protection proteins. In addition, partial 16S rRNA sequences from each of these isolates were sequenced to determine the identity of these isolates. Of the 85 isolates examined, 17 may represent potential novel species based on BLAST results. Greater than 50% of the isolates (48 out of 85) were found to not contain targeted tet efflux genes. Though minimum inhibitory concentrations ranged widely (16 – >256 mg/L), these values did not give an indication of the tet genes present. Ten new genera were identified that contain at least one tet efflux gene. Five other genera possessed tet efflux genes that were not found in these organisms previously. Interestingly, none of the isolates possessed any of the selected ribosomal protection protein genes. Though tetracycline resistance was found in bacteria isolated from a swine CAFO lagoon, it appears that the limited antibiotic use at this CAFO might have impacted the presence and diversity of tetracycline resistance genes.

Distribution of Tetracycline Resistance Genes and Transposons among Phylloplane Bacteria in Michigan Apple Orchards

1999 ◽  
Vol 65 (11) ◽  
pp. 4898-4907 ◽  
Author(s):  
Elise L. Schnabel ◽  
Alan L. Jones
Keyword(s):  
Resistance Genes ◽  
Tetracycline Resistance ◽  
Open Reading Frames ◽  
Resistant Bacteria ◽  
Apple Orchards ◽  
Bacterial Populations ◽  
Tetracycline Resistance Genes ◽  
The Family ◽  
Novel Variant ◽  
History Of

ABSTRACT The extent and nature of tetracycline resistance in bacterial populations of two apple orchards with no or a limited history of oxytetracycline usage were assessed. Tetracycline-resistant (Tcr) bacteria were mostly gram negative and represented from 0 to 47% of the total bacterial population on blossoms and leaves (versus 26 to 84% for streptomycin-resistant bacteria). A total of 87 isolates were screened for the presence of specific Tcrdeterminants. Tcr was determined to be due to the presence of Tet B in Pantoea agglomerans and other members of the family Enterobacteriacae and Tet A, Tet C, or Tet G in mostPseudomonas isolates. The cause of Tcr was not identified in 16% of the isolates studied. The Tcr genes were almost always found on large plasmids which also carried the streptomycin resistance transposon Tn5393. Transposable elements with Tcr determinants were detected by entrapment following introduction into Escherichia coli. Tet B was found within Tn10. Two of eighteen Tet B-containing isolates had an insertion sequence within Tn10; one had IS911 located within IS10-R and one had Tn1000 located upstream of Tet B. Tet A was found within a novel variant of Tn1721, named Tn1720, which lacks the left-end orfI of Tn1721. Tet C was located within a 19-kb transposon, Tn1404, with transposition genes similar to those of Tn501, streptomycin (aadA2) and sulfonamide (sulI) resistance genes within an integron, Tet C flanked by direct repeats of IS26, and four open reading frames, one of which may encode a sulfate permease. Two variants of Tet G with 92% sequence identity were detected.

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.

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