Evaluation of Virulence Factors and Antibiotic Sensitivity Pattern of Escherichia Coli Isolated from Extraintestinal Infections.

INTRODUCTION : Identification of virulence determinants among the clinically isolated microorganisms assumes greater significance in the patient management perspective. Among the hospitalized patients, extremes of age groups (neonatal and geriatric age patients), patients who are debilitated due to other associated medical conditions, patients taking immunosuppressive therapy, and patients undergoing major surgeries are prone to infections with previously nonpathogenic or opportunistic pathogens. Screening of the pathogenic potential of such bacteria and identifying their virulence factors and antimicrobial susceptibility patterns could be instrumental in better patient care and management. MATERIALS & METHODS : In this study, we evaluated the virulence determinants and antimicrobial susceptibility patterns of 100 clinical isolates of E. coli collected from extraintestinal infections and 50 control strains of E. coli. Hemolysin production, serum resistance, cell surface hydrophobicity, and gelatinase production were tested using standard laboratory procedures. RESULTS : Results showed that E. colistrains have a variable pattern of virulence markers that included hemolysin production (9%), cell surface hydrophobicity (9%), serum resistance (93%), and gelatinase production (2%). Antimicrobial susceptibility testing revealed a higher rate of resistance against cephalothin (84%) and ampicillin (98%). Susceptibility to amikacin (80%) and co-trimoxazole (47%) was variable and none of the test strains revealed resistance to imipenem. The control strains in contrast exhibited fewer virulence factors and the least resistance to antibiotics. CONCLUSION : In conclusion, the study results revealed that E. coli isolated from extraintestinal infections had demonstrated greater virulence and higher resistance to antibiotics as compared to the E. coli strains isolated from healthy individuals.

Hydrolyzed polyacrylamide grafted maize starch based microbeads: application in pH responsive drug delivery.

The present study details the synthesis, characterization and pharmaceutical application of hydrolysed polyacrylamide grafted maize starch (HPam-g-MS) as promising polymeric material for the development of pH responsive microbeads. Different grades of graft copolymer were synthesized by changing the net microwave irradiation time, while keeping all other factors constant. Acute oral toxicity study performed in rodents ensured the bio-safety of graft copolymer for clinical application. Various batches of aceclofenac loaded microbeads were prepared by ionic gelation method using synthesized graft copolymers and evaluated for formulation parameters. FTIR spectroscopy confirmed the chemical compatibility between drug and graft copolymer. Results of in vitro release study (USP type-II) carried out in two different pH media (pH 1.2 acid buffer and pH 7.4 phosphate buffer) showed that release rate of drug from developed microbeads was a function of both: (a) surrounding pH and (b) the matrix composition. The drug release was relatively higher at alkaline pH as compared to acidic pH and this feature is desirable from viewpoint of site specific drug delivery. A direct correlation was observed between percentage grafting and microbeads performance and it presents a scope for further research on application and optimization of HPam-g-MS based microbeads as drug delivery carriers.

Hydrolyzed polyacrylamide grafted carboxymethylxyloglucan based microbeads for pH responsive drug delivery.

The present study investigates the pharmaceutical application of hydrolyzed polyacrylamide grafted carboxymethylxyloglucan (HPam-g-CMXG), as promising polymeric material for the development of pH responsive microbeads. The graft copolymer was synthesized by conventional free radical polymerization method and saponified to enhance its functionality and characterized. An acute oral toxicity study ensured the bio-safety of developed copolymer for clinical application. Various batches of pH responsive spherical microbeads were developed and evaluated for the effect of process parameters on their overall performance. Result of in vitro drug release study (USP Type-II, paddle method) carried out in two different pH media (pH 1.2 and pH 7.4) showed a triphasic drug release pattern in all the formulations. Both the drug release and swelling of microbeads were significantly higher in simulated intestinal (alkaline) pH compared to simulated gastric (acidic) pH and this nature is desirable for targeted drug delivery. A strong correlation was observed between the process parameters and matrix composition and it directly influenced the drug transport mechanism. In conclusion, the hydrolyzed polyacrylamide grafted carboxymethylxyloglucan holds an immense potential to be explored pharmaceutically as new matrix material for the design of targeted drug delivery system.

Effect of electron correlations on magnetic excitations in the isovalently doped iron-based superconductor Ba(Fe(1-x)Ru(x))(2)As(2).

Magnetic correlations in isovalently doped Ba(Fe(1-x)Ru(x))(2)As(2) (x = 0.25, T(c) = 14.5 K; x = 0.35, T(c) = 20 K) are studied by elastic and inelastic neutron scattering techniques. A relatively large superconducting spin gap accompanied by a weak resonance mode is observed in the superconducting state in both samples. In the normal state, the magnetic excitation intensity is dramatically reduced with increasing Ru doping toward the optimally doped regime. Our results favor that the weakening of the electron-electron correlations by Ru doping is responsible for the dampening of the resonance mode, as well as the suppression of the normal state antiferromagnetic correlations near the optimally doped regime in this system.

Detection of various types of resistance patterns and their correlation with minimal inhibitory concentrations against clindamycin among methicillin-resistant Staphylococcus aureus isolates.

PURPOSE: The macrolide lincosamide streptogramin B (MLS B ) family of antibiotics serves as an alternative for the treatment of skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA). However, resistance to clindamycin too has emerged, which is of two types, inducible and constitutive. Therapeutic failure is common with inducible type of clindamycin resistance. This study was done to determine the various clindamycin resistance patterns in MRSA isolates and to compare them with minimal inhibitory concentration (MIC) of clindamycin. MATERIALS AND METHODS: Fifty MRSA isolates were studied by disc approximation test (D test) to detect inducible iMLS B resistance and MIC by agar dilution technique. RESULTS: Of the 50 isolates, 34 were sensitive to both clindamycin and erythromycin. 16 isolates showed different sensitivity patterns; nine of these were positive for D zone indicating inducible iMLS B resistance, five were positive for constitutive MLS B resistance and two showed possible efflux mechanism for macrolide resistance. Out of the 34 sensitive isolates, 5 showed isolated colonies (subpopulation) inside the clindamycin-sensitive zone. When these sub-populations were tested further, two were constitutive MLS B phenotypes, two were inducible iMLS B and one was HD (hazy D zone), which is D + with growth up to clindamycin disc (which is also considered as constitutive MLS B phenotype). Seven isolates showed an MIC of ≥4 µg/ml to clindamycin in spite of being susceptible to both erythromycin and clindamycin by Kirby Bauer disc diffusion technique. Out of these seven isolates, five were those which grew as subpopulation inside the clindamycin-sensitive zone. CONCLUSION: Detection of iMLS B resistance among MRSA helps to avoid treatment failure with clindamycin. Studying the subpopulation inside the clindamycin-sensitive zone raises the question of existence of hetero-resistance or some other mechanism, which needs further study.

Isolation, characterisation and cytotoxicity study of arjunolic acid from Terminalia arjuna.

Arjunolic acid (AA), a triterpenoid, was isolated from the ethyl acetate and methanol extracts of Terminalia arjuna core wood. The purity of AA was analysed by its melting point, FT-IR and NMR spectroscopy analyses. In vitro cytotoxicity was assessed using Ehrlich ascites carcinoma (EAC) and Dalton's lymphoma (DAL) cell lines by incubating with different concentrations of AA. The cancer cell death percentage at 100 µg concentrations of AA ranged between 66% and 70% on the DAL and EAC cell lines, respectively. This infers that AA causes considerable membrane damage to cancer cells.

Thyroid abscess due to Scedosporium apiospermum.

We report a case of thyroid abscess caused by Scedosporium apiospermum in a patient with cirrhosis of liver and autoimmune haemolytic anaemia. To date, there are no reports of isolation of this fungus from thyroid abscess.

Interpenetrating network hydrogel membranes of sodium alginate and poly(vinyl alcohol) for controlled release of prazosin hydrochloride through skin.

Interpenetrating network (IPN) hydrogel membranes of sodium alginate (SA) and poly(vinyl alcohol) (PVA) were prepared by solvent casting method for transdermal delivery of an anti-hypertensive drug, prazosin hydrochloride. The prepared membranes were thin, flexible and smooth. The X-ray diffraction studies indicated the amorphous dispersion of drug in the membranes. Differential scanning calorimetric analysis confirmed the IPN formation and suggests that the membrane stiffness increases with increased concentration of glutaraldehyde (GA) in the membranes. All the membranes were permeable to water vapors depending upon the extent of cross-linking. The in vitro drug release study was performed through excised rat abdominal skin; drug release depends on the concentrations of GA in membranes. The IPN membranes extended drug release up to 24 h, while SA and PVA membranes discharged the drug quickly. The primary skin irritation and skin histopathology study indicated that the prepared IPN membranes were less irritant and safe for skin application.

Interpenetrating network hydrogel beads of carboxymethylcellulose and egg albumin for controlled release of lipid lowering drug.

Novel interpenetrating network hydrogel beads of sodium carboxymethylcellulose and egg albumin loaded with a lipid lowering drug, simvastatin, were prepared by ionotropic gelation and covalent cross-linking method. The IPN beads were characterized by differential scanning colorimetric analysis, X-ray diffractometry to understand the crystalline nature of the drug after entrapment into IPN matrix. Fourier transform infrared spectroscopy was used to find the chemical stability of drug in the polymer matrix and scanning electron microscopy was performed to study the surface morphology. The ionically cross-linked beads were capable of releasing drug up to 7 h, whereas the drug release was extended up to 12 h in case of dual cross-linked beads. The beads which were prepared with higher concentration of glutaraldehyde released the drug more slowly. The release data were fitted to an empirical equation to determine the transport mechanism, which indicated the non-Fickian trend for drug transport.

Development of fast dispersible aceclofenac tablets: effect of functionality of superdisintegrants.

Aceclofenac, a non-steroidal antiinflammatory drug, is used for posttraumatic pain and rheumatoid arthritis. Aceclofenac fast-dispersible tablets have been prepared by direct compression method. Effect of superdisintegrants (such as, croscarmellose sodium, sodium starch glycolate and crospovidone) on wetting time, disintegration time, drug content, in vitro release and stability parameters has been studied. Disintegration time and dissolution parameters (t(50%) and t(80%)) decreased with increase in the level of croscarmellose sodium. Where as, disintegration time and dissolution parameters increased with increase in the level of sodium starch glycolate in tablets. However, the disintegration time values did not reflect in the dissolution parameter values of crospovidone tablets and release was dependent on the aggregate size in the dissolution medium. Stability studies indicated that tablets containing superdisintegrants were sensitive to high humidity conditions. It is concluded that fast-dispersible aceclofenac tablets could be prepared by direct compression using superdisintegrants.

Alginate-coated alginate-polyethyleneimine beads for prolonged release of furosemide in simulated intestinal fluid.

Furosemide-loaded calcium alginate (ALG), calcium alginate-polyethyleneimine (ALG-PEI) and alginate-coated ALG-PEI (ALG-PEI-ALG) beads were prepared by ionotropic/polyelectrolyte complexation method to achieve controlled release of the drug. Effects of several formulation factors on the characteristics of the beads were investigated. Although variation in formulation factors did not influence the drug-loading efficiency (DLE) of ALG beads, rapid release of the drug in simulated intestinal fluid (SIF) could not be prevented. PEI treatment of ALG beads, however, prolonged the drug release considerably. Ionic interaction, as appeared from FTIR studies, between alginate and PEI led to the formation of polyelectrolyte complex membrane, the thickness of which was dependent on the conditions of PEI treatment as demonstrated by scanning electron microscopy (SEM). The membrane acted as a physical barrier to drug release from ALG-PEI beads. Alginate coating of ALG-PEI beads further prolonged the release of the drug by increasing membrane thickness and reducing swelling of the beads possibly by blocking the surface pores. Differential scanning calorimetry (DSC) study indicated that drug was not degraded by PEI treatment. The release data from ALG-PEI beads showed a good fit in power law expression, whereas the release data from ALG-PEI-ALG beads were found to fit in modified power law expression, and the mechanism of drug release changed from super case II transport to nearly Fickian transport, depending on the degree of gelation and formation of polyelectrolyte complex membrane.

Bilateral renal angiomyolipoma in association with tuberous sclerosis.

Renal angiomyolipoma with tuberous sclerosis has not yet been reported in Indian literature. We report a case of bilateral angiomyolipoma associated with tuberous sclerosis in a 25 year old man.