Integron types, gene cassettes, antimicrobial resistance genes and plasmids of Shigella sonnei isolates from outbreaks and sporadic cases in Taiwan

Abstract

This study analysed the presence, location and transferability of integrons and antibiotic resistance genes in 103 Shigella sonnei outbreak isolates and in 32 sporadic isolates from Taiwan. Multiple antimicrobial resistance was common in both outbreak (95 %) and sporadic (97 %) isolates. Class 1 integrons were present in 34 outbreak isolates (33 %) and in six sporadic isolates (19 %). This study is the first, to our knowledge, to identify an atypical sul3-associated class 1 integron carrying the estX-psp-aadA2-cmlA-aadA1-qacH cassette array in Shigella. Class 2 integrons carrying the dfr1-sat2-aadA1 cassette array were predominant in outbreak isolates (90 %) but were not present in sporadic isolates. Other antimicrobial resistance genes not associated with integrons were found to encode resistance to ampicillin (bla TEM ), chloramphenicol (cat1), sulfonamide (sul2) and tetracycline (tetA and tetB). The most common plasmid size was 130 kb (observed in 43 and 97 % of 1998 outbreak and sporadic isolates, respectively). In conclusion, the plasmid location of resistance genes and horizontal plasmid transfer promote the spread of multiple resistance genes in outbreak and sporadic isolates of S. sonnei.

Antimicrobial resistance and distribution of sul genes and integron-associated intI genes among uropathogenic Escherichia coli in Queensland, Australia

“…For instance, acquisition of resistance genes by horizontal transfer is the main role in the development of MDR strains (Chang et al, 2011;Moritz & Hergenrother, 2006). Naturally, the recipient microorganism would be able to colonize a new environment when selective pressures select for variants that can survive these pressures (Croxen & Finlay, 2010).…”

“…Escherichia coli is the primary aetiological agent, accounting for 75-90 % cases of UTI (Gupta et al, 2001;Kaper et al, 2004;Nicolle, 2002). The acquisition of resistance genes by horizontal transfer is currently thought to play a major role in the development of multi-drugresistant (MDR) strains because a substantial proportion of the resistance genes are located on conjugative plasmids, transposons, insertion sequences and integrons (Chang et al, 2011;Fierer & Guiney, 1999;Moritz & Hergenrother, 2006). Integrons are mobile DNA elements with the ability to integrate and express gene cassettes by site-specific recombination (Mazel, 2006;Rowe-Magnus & Mazel, 2002).…”

Association of blaCTX-M-15 and qnr genes in multidrug-resistant Salmonella Typhimurium and Shigella spp from India

“…All four STM were found to harbour class 1 integrons. The resistant determinants of trimethoprimsulfamethoxazole were known to be associated with class1 and class 2 integrons [8].…”

Perfil de resistência a antimicrobianos de amostras de <i>Escherichia coli</i> enteropatogênica atípica.

“…As sulfonamidas são derivadas da sulfanilamida e possuem estrutura semelhante ao ácido paraminobenzóico (PABA O gene sul1 é encontrado juntamente com outros genes de resistência no segmento conservado 3`de integrons de classe1, enquanto sul2 geralmente é encontrado em pequenos plasmídeos não conjugativos ou em grandes plasmídeos transmissíveis (ANTUNES et al, 2005;BYRNE-BAILEY et al, 2009;CHANG et al, 2011;SKÖLD, 2000;SKÖLD, 2001). O gene sul3 foi inicialmente encontrado em plasmídeos, porém posteriormente foi descoberto que estão localizados ao segmento conservado de integrons de classe 1 (CHANG et al, 2011;CHUANCHUEN;KHEMTONG, 2008;KOOWATANANUKUL;PEIRANO et al, 2005).…”

“…O gene sul3 foi inicialmente encontrado em plasmídeos, porém posteriormente foi descoberto que estão localizados ao segmento conservado de integrons de classe 1 (CHANG et al, 2011;CHUANCHUEN;KHEMTONG, 2008;KOOWATANANUKUL;PEIRANO et al, 2005).…”