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.

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.

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.