Terrestre

URI permanente para esta comunidadhttps://digital.inta.es/handle/20.500.12666/82

Buscar

Mostrando 1 - 2 de 2

Acceso Abierto
Phenotypic and genetic analyses of 111 clinical and environmental O1, O139, and non-O1/O139 Vibrio cholerae strains from different geographical areas
(Cambridge University Press, 2012-08-05) Sellek Cano, Ricela; Niemcewicz, Marcin; Olsen, Jaran; Bassy Alvarez, Olga; Lorenzo Lozano, P.; Martí, L.; Roszowiak, A.; Kocik, J.; Cabria Ramos, Juan Carlos
A total of 111 clinical and environmental O1, O139 and non-O1/O139 Vibrio cholerae strains isolated between 1978 and 2008 from different geographical areas were typed using a combination of methods: antibiotic susceptibility, biochemical test, serogroup, serotype, biotype, sequences containing variable numbers of tandem repeats (VNTRs) and virulence genes ctxA and tcpA amplification. As a result of the performed typing work, the strains were organized into four clusters: cluster A1 included clinical O1 Ogawa and O139 serogroup strains (ctxA + and tcpA +); cluster A2 included clinical non-O1/O139 strains (ctxA − and tcpA −), as well as environmental O1 Inaba and non-O1/O139 strains (ctxA − and tcpA −/tcpA +); cluster B1 contained two clinical O1 strains and environmental non-O1/O139 strains (ctxA − and tcpA +/tcpA −); cluster B2 contained clinical O1 Inaba and Ogawa strains (ctxA + and tcpA +). The results of this work illustrate the advantage of combining several typing methods to discriminate between clinical and environmental V. cholerae strains.
Restringido
Rapid identification of Bacillus anthracis by real-time PCR with dual hybridization probes in environmental swabs
(Elsevier, 2017-11-04) Bassy Alvarez, Olga; Jiménez, Oscar; Ortega García, María Victoria; Granja, Carmen; Cabria Ramos, Juan Carlos
In the present study, we report the development of a real-time PCR assay for the identification of Bacillus anthracis, based on the amplification of a unique chromosomal marker, the E4 sequence, with dual hybridization probes. The assay was evaluated using a panel of ten B. anthracis strains, two B. anthracis isolates from human clinical samples, 12 B. anthracis environmental swabs and 40 non- B. anthracis strains. All 12 B. anthracis strains and clinical isolates were correctly detected, and the method did not show cross-reactions with other micro-organisms. Likewise, the E4 sequence was not found in those strains of B. thuringiensis and B. cereus closely related (homology > 90%) to B. anthracis by computer analysis. On the other hand, this molecular assay showed a high analytical sensitivity, 3.5 genome equivalents per reaction at 95% probability. Furthermore, the real-time PCR assay allowed sequence-specific detection of the amplicon (melting peak with a Tm of 63.5 °C ± 0.5 °C) without post-amplification procedures, which offers an additional advantage over other qPCR assays for B. anthracis detection. Finally, the performance of the method was successfully evaluated in 12 environmental samples. In summary, we have developed a rapid and specific method for the molecular identification of Bacillus anthracis in environmental samples.

Buscar

Examinando Terrestre por Autor "Bassy Alvarez, Olga"