Sequence analysis of partial toxR gene from Philippine Vibrio isolates and design of toxR-targeted primers for detection

Amplification and sequence analysis of the full length toxR gene in Vibrio harveyi

“…4), there is wider degree of divergence in toxR gene between V. harveyi and closely related Vibrio species (particularly between V. harveyi vs V. campbellii and V. harveyi vs V. parahaemolyticus) compared to divergence in the 16S rRNA gene. Whereas, 16S rRNA gene sequence analysis is not successful in distinguishing V. harveyi from closely related species, particularly, V. campbellii (Rañoa and Hedreyda, 2005), the toxR divergent regions as well as the total gene sequence deviation between V. harveyi and V. campbellii could easily help distinguish one from the other.…”

Rapid diagnosis of vibriosis and white spot syndrome (WSS) in the culture of shrimp, Penaeus monodon in Philippines

“…These have been routinely used in various shrimp health laboratories all over the world. On the other hand, PCR protocols to detect pathogenic Vibrios have also been developed (Maeda et al 2002;Hedreyda 2003, 2004;Rañoa and Hedreyda 2005;Castroverde et al 2006;Franco and Hedreyda 2006) and Thailand (Thaithongnum et al 2006). Most of the PCR assays for the detection of WSSV have been tested in field assays, but the protocols for detecting pathogenic Vibrios have been developed using established strains of Vibrio spp.…”

Differential detection of vibrios pathogenic to shrimp by multiplex PCR

“…In addition to these two species, Vibrio isolates from infected shrimps in different parts of the Philippines, were observed to cause high mortalities of shrimp postlarvae (De la Peña et al, 2001). These isolates were identified on the basis of biochemical tests to belong to either V. harveyi or V. campbellii but were observed to exhibit characteristics distinct from type strains of both species (Cortado et al, 2004;Rañoa and Hedreyda, 2005 The research was focused on the multiplex polymerase chain reaction (PCR) differential detection of shrimp pathogens Vibrio harveyi, Vibrio campbellii and isolates from a variant strain of Vibrio (referred to as Philippine Vibrio isolates in this study) exhibiting characteristics distinct from these two species. Sequence alignment of the hemolysin gene from type strains Vibrio harveyi (NBRC 15634) and Vibrio campbellii (NBRC 15631), as well as 10 variant Philippine Vibrio isolates, was performed in order to design a set of hemolysin-targeted primers for the specific detection of the Philippine Vibrio isolates.…”

“…Sequences from both hemolysin and toxR genes have been used to develop single locus PCR-based protocols for the detection of Vibrio species (Bej et al, 1999;Kim et al, 1999;Lee et al, 1998;Vuddhakul et al, 2000). Single locus toxR and hemolysin gene-targeted PCR were developed for the specific detection of type strain V. harveyi Hedreyda, 2003, 2004) and a toxR-targeted PCR was reported for the detection of shrimp pathogenic Philippine Vibrio isolates (Rañoa and Hedreyda, 2005). In this study, however, hemolysin and toxR-targeted multiplex PCR was used for the differential detection of three strains of Vibrio shrimp pathogens.…”