5 research outputs found
Characterization of ceftriaxone-resistant Aeromonas spp. isolates from stool samples of both children and adults in Southern India
Background: Aeromonas species can cause a wide spectrum of illnesses
varying from intestinal to extra intestinal and vary in their
susceptibility to different antibiotics. The current study was
undertaken to characterize the third generation cephalosporin-resistant
strains of Aeromonas spp. which were isolated from stool specimens.
Methods: Out of a total of 2780 stool samples, 29 Aeromonas spp. were
identified, out of which, 9 were resistant to ceftriaxone by the
Kirby-Bauer antibiotic testing method. These strains were subjected to
minimum inhibitory concentration (MIC) determination by agar dilution
for ceftriaxone. Phenotypic and genotypic testing of AmpC
beta-lactamase and extended spectrum beta-lactamase (ESBL) were
performed. Gene transfer was carried out to demonstrate
transmissibility of these genetic elements by conjugation experiments.
Results: Out of the 29 strains, 9 showed MIC of 654 \u3bcg/ml.
Seven out of 9 showed presence of blaCTX-M, while 2 more strains showed
the presence of inducible AmpC beta-lactamase and presence of MOX gene.
Gene transfer experiments showed that these elements were transmissible
to recipient ( Escherichia coli J53 strain) in the presence of
ceftriaxone. Conclusions: Dissemination of these resistance
determinants like plasmids is pivotal in the spread of these resistance
genes into the aquatic environment into organisms like Aeromonas. This
may further limit the future use of antibiotics for the treatment of
diarrhoeal diseases. Hence, detection and antibiotic susceptibility
testing of Aeromonas spp. should be performed when isolated from stool
samples
Comparison of nested-multiplex, Taqman & SYBR Green real-time PCR in diagnosis of amoebic liver abscess in a tertiary health care institute in India
Background & objectives: Amoebiasis is a common parasitic infection caused by Entamoeba histolytica and amoebic liver abscess (ALA) is the most common extraintestinal manifestation of amoebiasis. The aim of this study was to standardise real-time PCR assays (Taqman and SYBR Green) to detect E. histolytica from liver abscess pus and stool samples and compare its results with nested-multiplex PCR.
Methods: Liver abscess pus specimens were subjected to DNA extraction. The extracted DNA samples were subjected to amplification by nested-multiplex PCR, Taqman (18S rRNA) and SYBR Green real-time PCR (16S-like rRNA assays to detect E. histolytica/E. dispar/E. moshkovskii). The amplification products were further confirmed by DNA sequence analysis. Receiver operator characteristic (ROC) curve analysis was done for nested-multiplex and SYBR Green real-time PCR and the area under the curve was calculated for evaluating the accuracy of the tests to dignose ALA.
Results: In all, 17, 19 and 25 liver abscess samples were positive for E. histolytica by nested-multiplex PCR, SYBR Green and Taqman real-time PCR assays, respectively. Significant differences in detection of E. histolytica were noted in the real-time PCR assays evaluated ( P<0.0001). The nested-multiplex PCR, SYBR Green real-time PCR and Taqman real-time PCR evaluated showed a positivity rate of 34, 38 and 50 per cent, respectively. Based on ROC curve analysis (considering Taqman real-time PCR as the gold standard), it was observed that SYBR Green real-time PCR was better than conventional nested-multiplex PCR for the diagnosis of ALA.
Interpretation & conclusions: Taqman real-time PCR targeting the 18S rRNA had the highest positivity rate evaluated in this study. Both nested multiplex and SYBR Green real-time PCR assays utilized were evaluated to give accurate results. Real-time PCR assays can be used as the gold standard in rapid and reliable diagnosis, and appropriate management of amoebiasis, replacing the conventional molecular methods
Comparison of nested-multiplex, Taqman & SYBR Green real-time PCR in diagnosis of amoebic liver abscess in a tertiary health care institute in India
Background & objectives: Amoebiasis is a common parasitic infection caused by Entamoeba histolytica and amoebic liver abscess (ALA) is the most common extraintestinal manifestation of amoebiasis. The aim of this study was to standardise real-time PCR assays (Taqman and SYBR Green) to detect E. histolytica from liver abscess pus and stool samples and compare its results with nested-multiplex PCR.
Methods: Liver abscess pus specimens were subjected to DNA extraction. The extracted DNA samples were subjected to amplification by nested-multiplex PCR, Taqman (18S rRNA) and SYBR Green real-time PCR (16S-like rRNA assays to detect E. histolytica/E. dispar/E. moshkovskii). The amplification products were further confirmed by DNA sequence analysis. Receiver operator characteristic (ROC) curve analysis was done for nested-multiplex and SYBR Green real-time PCR and the area under the curve was calculated for evaluating the accuracy of the tests to dignose ALA.
Results: In all, 17, 19 and 25 liver abscess samples were positive for E. histolytica by nested-multiplex PCR, SYBR Green and Taqman real-time PCR assays, respectively. Significant differences in detection of E. histolytica were noted in the real-time PCR assays evaluated ( P<0.0001). The nested-multiplex PCR, SYBR Green real-time PCR and Taqman real-time PCR evaluated showed a positivity rate of 34, 38 and 50 per cent, respectively. Based on ROC curve analysis (considering Taqman real-time PCR as the gold standard), it was observed that SYBR Green real-time PCR was better than conventional nested-multiplex PCR for the diagnosis of ALA.
Interpretation & conclusions: Taqman real-time PCR targeting the 18S rRNA had the highest positivity rate evaluated in this study. Both nested multiplex and SYBR Green real-time PCR assays utilized were evaluated to give accurate results. Real-time PCR assays can be used as the gold standard in rapid and reliable diagnosis, and appropriate management of amoebiasis, replacing the conventional molecular methods