<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Molecular characterization of virulence-associated protein (Vap) family genes of pathogenic <i style="mso-bidi-font-style:normal">Rhodococcus equi</i> isolates from clinical cases of Indian equines</span>

Abstract

<span style="font-size:9.0pt;mso-ansi-language:EN-IN;mso-bidi-font-weight: bold">Virulence-associated plasmid (<i>Vap</i>) genes of clinical isolates of <i>Rhodococcus equi </i><span style="mso-bidi-font-style:italic">were characterized. <span style="font-size:9.0pt;mso-bidi-font-weight:bold" lang="EN-GB">Isolates were identified by 16S rRNA, <i style="mso-bidi-font-style:normal">cho</i>E and <i style="mso-bidi-font-style: normal">tra</i>A gene<span style="mso-bidi-font-weight:bold"> PCR, followed by amplification, cloning and sequencing of 7 <i style="mso-bidi-font-style:normal">V</i><i style="mso-bidi-font-style:normal">ap</i><span style="mso-bidi-font-weight: bold"> genes. <span style="font-size:9.0pt;mso-ansi-language:EN-IN;mso-bidi-font-weight: bold">The isolates were found positive for <i style="mso-bidi-font-style: normal"><span style="font-size:9.0pt;mso-bidi-font-weight:bold" lang="EN-GB">vap</span></i><span style="font-size:9.0pt;mso-bidi-font-weight:bold" lang="EN-GB">A gene family. The comparative sequence analysis of <i style="mso-bidi-font-style:normal">vap</i> genes revealed 99-100% similarity at both nt and aa levels with all sequences. The aa sequences of the predicted Vap proteins<span style="font-size: 9.0pt;mso-ansi-language:EN-IN;mso-bidi-font-weight:bold"> exhibited a high degree of similarity to each other, especially at the carboxy terminal ends. Invariable point mutations were observed in Vap proteins<span style="font-size:9.0pt;mso-bidi-font-weight: bold" lang="EN-GB">.<span style="font-size:9.0pt;mso-ansi-language:EN-IN;mso-bidi-font-weight: bold"> The changes did not cause alteration in hydropathicity and secondary structures in VapA & H proteins. Few major changes in polarity and structures were observed in VapD, E and G proteins. Phylogenetic analysis revealed that all <i style="mso-bidi-font-style: normal">Vap</i> genes followed similar branching pattern<span style="font-size:9.0pt;mso-bidi-font-weight:bold" lang="EN-GB"> except isolate from Bahadurgarh (BBG163). <span style="font-size:9.0pt;mso-ansi-language: EN-IN;mso-bidi-font-weight:bold">We conclude that VapA<span style="font-size:9.0pt;mso-bidi-font-weight:bold" lang="EN-GB"> is highly conserved and plays a major role in pathogenesis<span style="font-size:9.0pt;mso-ansi-language: EN-IN;mso-bidi-font-weight:bold">. This is the first report of sequence analysis and phylogenetic studies of <i style="mso-bidi-font-style:normal">Vap</i> gene family of clinical virulent isolates of <i style="mso-bidi-font-style: normal">R. equi </i>from India.<b style="mso-bidi-font-weight:normal"></b>

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