ÿþ<HTML><HEAD><TITLE>25º Congresso Brasileiro de Microbiologia </TITLE><link rel=STYLESHEET type=text/css href=css.css></HEAD><BODY aLink=#ff0000 bgColor=#FFFFFF leftMargin=0 link=#000000 text=#000000 topMargin=0 vLink=#000000 marginheight=0 marginwidth=0><table align=center width=700 cellpadding=0 cellspacing=0><tr><td align=left bgcolor=#cccccc valign=top width=550><font face=arial size=2><strong><font face=Verdana, Arial, Helvetica, sans-serif size=3><font size=1>25º Congresso Brasileiro de Microbiologia </font></font></strong><font face=Verdana size=1><b><br></b></font><font face=Verdana, Arial,Helvetica, sans-serif size=1><strong> </strong></font></font></td><td align=right bgcolor=#cccccc valign=top width=150><font face=arial size=2><strong><font face=Verdana, Arial, Helvetica, sans-serif size=1><font size=1>ResumoID:2127-1</font></em></font></strong></font></td></tr><tr><td colspan=2><br><br><table align=center width=700><tr><td>Área: <b>Microbiologia Clinica ( Divisão A )</b><p align=justify><strong>CLASS 1 INTEGRON HARBORING <EM>BLA</EM><SUB>CTX</SUB> GENE IN <EM>KLEBSIELLA PNEUMONIAE</EM>.</strong></p><p align=justify><b><u>Marinalda Anselmo Vilela </u></b> (<i>UPE</i>); <b>Anna Carolina Soares Almeida </b> (<i>UPE</i>); <b>Beathriz Godoy Vilela Barbosa </b> (<i>UPE</i>); <b>Felipe Lira de Sá Cavalcanti </b> (<i>UPE</i>); <b>Marcia Maria Camargo de Morais </b> (<i>UPE</i>); <b>Marcos Antonio de Morais Junior </b> (<i>UFPE</i>)<br><br></p><b><font size=2>Resumo</font></b><p align=justify class=tres><font size=2><P align=justify><SPAN lang=EN-US style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman'; mso-fareast-language: ZH-CN; mso-fareast-font-family: SimSun; mso-ansi-language: EN-US; mso-bidi-language: AR-SA">An integron is defined as a genetic element that possesses a site for integration of gene cassettes, <I>attI</I>, responsible for these site-especific recombination events. A class 1 integron consists of <I>intI</I> integrase-encoding gene<I> </I>in the 5 conserved sequence (5 CS) and the conserved resistance genes <I style="mso-bidi-font-style: normal">qacE&#8710;</I><SPAN style="mso-bidi-font-style: italic">1 and <I>sul1</I></SPAN> in the 3 conserved sequence (3 CS). These class 1 integrons are the most prevalent in clinic isolates. However, some other class 1 integron structures have been identified, in which there is one 5 CS and two copies of the 3 CS. The aim of this work was to describe the prevalence of class 1 integrons in ESBL-producing <I>Klebsiella pneumoniae</I> isolates and to perform the PCR-based mapping of an <I>bla<SUB>CTX</SUB></I><SUB>-M</SUB> containing class 1 integron.<B> </B>A total of 55 nonreplicate clinical isolates of previously identified as ESBL-producing <I style="mso-bidi-font-style: normal"><SPAN style="mso-bidi-font-weight: bold">K. pneumoniae</SPAN></I><SPAN style="mso-bidi-font-weight: bold">, collected from june 2002 to june 2005 was analysed for the presence of class 1 integrons. Following DNA extraction by boiling procedure, supernatant (1</SPAN></SPAN><SPAN lang=EN-US style="FONT-SIZE: 12pt; FONT-FAMILY: Symbol; mso-bidi-font-weight: bold; mso-fareast-language: ZH-CN; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: SimSun; mso-ansi-language: EN-US; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-char-type: symbol; mso-symbol-font-family: Symbol"><SPAN style="mso-char-type: symbol; mso-symbol-font-family: Symbol">m</SPAN></SPAN><SPAN lang=EN-US style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman'; mso-bidi-font-weight: bold; mso-fareast-language: ZH-CN; mso-fareast-font-family: SimSun; mso-ansi-language: EN-US; mso-bidi-language: AR-SA">L) was used as template for amplification reactions, using specific primers to detect the class 1 integron components and to carry out the integron PCR-mapping. </SPAN><SPAN lang=EN-US style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman'; mso-fareast-language: ZH-CN; mso-fareast-font-family: SimSun; mso-ansi-language: EN-US; mso-bidi-language: AR-SA">Results showed that 90.1% of the ESBL-producing <I style="mso-bidi-font-style: normal">K. pneumoniae</I> showed to be integron-positive isolates. In those isolates, the findings suggested that the <I>bla</I><SUB>CTX</SUB> gene was only integron-located. The results of specific PCR for the variable region 5 CS-3 CS in nine isolates showed three different sizes of 700, 1448 and 1633 bp. PCR mapping of a representative <I>bla</I><SUB>CTX-M </SUB>carrying class 1 integron showed a structure similar to unusual <I>sul1</I> type integrons, with two copies of the 3 CS and the <I>bla</I><SUB>CTX</SUB> gene located outside the variable region. Sequence analysis of the variable region showed the presence of the genes <I style="mso-bidi-font-style: normal"><SPAN style="mso-bidi-font-weight: bold">dfrA,</SPAN></I><SPAN style="mso-bidi-font-weight: bold; mso-bidi-font-style: italic"> with</SPAN><SPAN style="mso-bidi-font-weight: bold"> 591 bp and <I style="mso-bidi-font-style: normal">aadA, with</I> 800 bp, which code the enzymes dihydrofolate reductase and adenyltransferases, respectively. </SPAN><SPAN style="mso-spacerun: yes">&nbsp;</SPAN>In conclusion, there was a high prevalence of class 1 integrons in ESBL-producing isolates analysed. The unusual class 1 integron carrying <I>bla</I><SUB>CTX-M </SUB>showed similarities to others described also in south America, suggesting the in course dissemination of such integron structures.</SPAN></P></font></p><br><b>Palavras-chave: </b>&nbsp;ESBL, integron, blaCTX</td></tr></table></tr></td></table></body></html>