Diversity of tetracycline resistance genes in bacteria from aquaculture sources in Australia

Abstract

Aims: To determine the genetic determinants responsible for tetracycline resistance in oxytetracycline resistant bacteria from aquaculture sources in Australia. Methods and Results: Twenty of 104 (19%) isolates tested were resistant to oxytetracycline (MIC ≥ 16 μg ml−1). Using polymerase chain reaction (PCR) amplification, one or more tet genes were detected in 15/20 (75%) isolates tested, but none were found in 5/20 (25%). tetM (50%) was the most common determinant, followed by tetE (45%), tetA (35%) and tetD (15%). Five of 12 oxytetracycline resistant isolates studied were able to transfer their R‐plasmid to Escherichia coli recipients of chicken, pig and human origin. tetA, tetD and tetM were found to be transferred while tetE was not transferred. Southern hybridization and PCR were used to confirm transfer of determinants. Conclusions: Bacterial isolates from aquaculture sources in Australia harbour a variety of tetracycline resistance genes, which can be transferred to other bacteria of different origin. Significance and Impact of the Study: Bacteria from aquaculture sources in Australia contribute to the resistance gene pool reservoir. The in vitro transfer of tetracycline R‐plasmid from aquatic bacteria to E. coli isolates from various sources is an indication of the potential public health risk associated with these resistance determinants.

Resistance Determinants of Pseudomonas Species from Aquaculture in Australia

“…There is limited information on the occurrence of integrons and other resistance genes in bacteria of aquaculture origin in Australia [38,39]. Integrons are known to have the capacity to carry many antibiotic resistance genes and so the resistant Pseudomonas strains were investigated for the presence or absence of integrase genes for class 1, class 2 and class 3 integrons.…”

Pharmacodynamics of Doxycycline and Tetracycline against Staphylococcus pseudintermedius: Proposal of Canine-Specific Breakpoints for Doxycycline

“…All isolates belonging to the tetracycline-resistant subpopulation were screened by PCR for the presence of resistance genes previously reported in this staphylococcal species, i.e., tet(K), tet(M), tet(L), and tet(O) genes. Primers and cycling conditions were the same as reported previously (7,8).…”

Detection of 140 clinically relevant antibiotic-resistance genes in the plasmid metagenome of wastewater treatment plant bacteria showing reduced susceptibility to selected antibiotics

“…vanC, ampC, mecA (Schwartz et al, 2003;Volkmann et al, 2004), or on genes conferring resistance to a specific class of antimicrobial compounds, e.g. b-lastams (Henriques et al, 2006a, b), chloramphenicol (Dang et al, 2008), or tetracyclines (Akinbowale et al, 2007;Chee-Sanford et al, 2001;Guillaume et al, 2000;Smith et al, 2004).…”