Browsing by Author "A. Gaur"

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Increased prevalence of extended spectrum β lactamase producers in neonatal septicaemic cases at a tertiary referral hospital
(Medknow Publications and Media Pvt. Ltd, 2008) A. Bhattacharjee; M. Sen; P. Prakash; A. Gaur; S. Anupurba
Emergence of extended spectrum β lactamases (ESBLs) producing strains of gram negative bacteria, as one of the leading cause of septicaemia often complicates the clinical and therapeutic outcome. The present study was undertaken to investigate the prevalence of ESBLs in bacteria isolated from neonatal septicaemic cases along with their antimicrobial sensitivity pattern. Blood samples were collected from 243 suspected cases of neonatal septicaemia. Apart from susceptibility testing, all the gram negative isolates were subjected to phenotypic tests for ESBL production. Amongst the positive test samples (n = 115), 84 were gram negative rods. ESBL was detected in 26 (32%) isolates. Results indicate that routine ESBL detection should be made imperative and empirical use of third generation cephalosporins must be discouraged.
Microstructure-magnetotransport correlation in La0.7Ca0.3MnO3
(2007) P.K. Siwach; R. Prasad; A. Gaur; H.K. Singh; G.D. Varma; O.N. Srivastava
Microstructure-magnetotransport correlation has been studied in polycrystalline La0.7Ca0.3MnO3 having varying grain size. Single phase samples were synthesized through the polymeric precursor route and grain size has been varied by heat treatment of the precursor in the temperature range of 500-1300 °C. Larger grain size has resulted in a reduction of the orthorhombicity caused possibly by decrease in intragranular strain. PM-FM phase transition sets on around ∼270 K; the mid point TC being ∼256, 260, 262 and 265 K, respectively, for samples having grain size ∼25, 40, 100 and 700 nm. The IM transition temperature, despite being suppressed in small grain samples equals to TC in the largest grain samples. Grain size variation from ∼25 to ∼700 nm causes decrease in resistivity by more than two orders of magnitude. The low field magnetoresistance (LFMR) is observed to be strongly correlated with the microstructural/transport parameters such as the grain size and the resistivity. In contrast to the generally observed results, the LFMR increases with grain size and the maximum LFMR is obtained when the grain size is ∼100 nm. We propose that for every composition there exist an optimum grain size at which the LFMR reaches a maximum. This optimal grain size may vary from sample to sample and may also depend on the synthesis technique. © 2006 Elsevier B.V. All rights reserved.
Observation on integron carriage among clinical isolates of Klebsiella pneumoniae producing extended-spectrum β-lactamases
(Medknow Publications and Media Pvt. Ltd, 2010) A. Bhattacharjee; M.R. Sen; P. Prakash; A. Gaur; S. Anupurba; G. Nath
Purpose: Klebsiella pneumoniae is considered an important pathogen causing nosocomial and community-acquired infections and is often associated with the production of extended-spectrum -lactamases (ESBL) belonging to SHV and CTX-M families, which are frequently described as a part of complex integrons, facilitate their horizontal transfer to other related as well as unrelated microbes. The present study was undertaken to investigate the occurrence and characterization of integrons among K pneumoniae isolates producing ESBL in a tertiary referral hospital. Materials and Methods: A total of 136 clinical isolates of K pneumoniae were investigated for the presence of ESBL. Their ESBL genes were characterized by multiplex polymerase chain reaction (PCR). Integrase gene PCR was performed to detect the presence of integron. The isolates were further typed by random amplification of polymorphic DNA (RAPD). Result: Out of 136 K pneumoniae isolates, 63 (46%) were confirmed to be ESBL producers. SHV (68%) and CTX-M (67%) ESBL genes were the most common in our study. Of the 63 ESBL-positive isolates, 58 (92%) strains carried integrons; 52 strains (82%) carried only class 1 integron, whereas 6 (9%) isolates harboured both class 2 integrons and the class 1 gene. However, in ESBL negatives, only 29 (40%) strains were positive for class 1 integron and none for class 2 integron. Conclusion: The presence of class 2 integron amongst ESBL-producing K pneumoniae is being described for the first time in this part of the world. The findings of this study strongly suggest that integrons have a role in the dissemination of ESBL-mediated resistance among the nosocomial isolates of K pneumonia.
Observations on carbapenem resistance by minimum inhibitory concentration in nosocomial isolates of acinetobacter species: An experience at a tertiary care hospital in north India
(2008) A. Gaur; A. Garg; P. Prakash; S. Anupurba; T.M. Mohapatra
Acinetobacter species are emerging as an important nosocomial pathogen. Multidrug-resistant Acinetobacter spp. has limited the option for effective treatment. Although carbapenems are effective for the treatment of such infections, resistance to this drug has recently been reported. This study was undertaken to assess resistance to carbapenem in clinical isolates of Acinetobacter spp. from hospitalized patients by both disc-diffusion and minimum inhibitory concentration (MIC) methods. All clinical samples from suspected cases of nosocomial infections were processed, and 265 isolates were identified as Acinetobacter species. These isolates were tested for antibiotic resistance by the disc-diffusion method with 14 antimicrobials, including meropenem and imipenem. Thereafter, all Acinetobacter species were subjected to MIC for meropenem. More than 80% resistance to second- and third-generation cephalosporins, aminoglycosides, and quinolones was recorded. Thirty percent of the strains were resistant to cefoperazone/sulbactam. Resistance to meropenem was observed in 6.4% of Acinetobacter spp. while 8.3% of the isolates showed intermediate resistance detected by MIC. All carbapenem-resistant/intermediate strains were also resistant to other (>10) antibiotics tested by the disc-diffusion method. The rising trend of resistance to carbapenem poses an alarming threat to the treatment for such infections. Regular monitoring, judicious prescription, and early detection of resistance to carbapenem are necessary to check further dissemination of drug resistance in Acinetobacter spp. © International Centre for Diarrhoeal Disease Research, Bangladesh.
Prevalence of inducible AmpC β-lactamase-producing Pseudomonas aeruginosa in a tertiary care hospital in northern India [1]
(Medknow Publications and Media Pvt. Ltd, 2008) A. Bhattacharjee; S. Anupurba; A. Gaur; M. Sen
[No abstract available]