Browsing by Author "Ballal, Mamatha"
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Item Enteroaggregative Escherichia coli diarrhea in Manipal.(2005-07-09) Ballal, Mamatha; Ramamurthy, TItem Identification of enteroaggregative Escherichia coli in infants with acute diarrhea based on biofilm production in Manipal, south India.(2008-01-02) Bangar, Raju; Ballal, MamathaBackground: Enteroaggregative Escherichia coli (EAEC) is an emerging enteric pathogen that causes persistent diarrhea among infants, both in developing and industrialized countries. The EAEC strains adhere to epithelial cell surface, to the glass substratum and to each other in a distinctive stacked brick-formation. Thus, gold standard for identification of EAEC remains the HEp-2 cell adherence test, which is time consuming and requires specialized facilities. Aim: To evaluate the usefulness of quantitative biofilm assay to screen for EAEC from children with acute diarrhea. Materials and Methods: A total of 100 E. coli strains were collected from acute diarrheal cases from December 2005 to November 2006. The strains were screened for biofilm production using microtiter plate method. The biofilm in the microtiter plate was visualized after staining with crystal violet and was quantified using enzyme immunosorbent assay plate reader. The Aggregative plasmid and Heat stable toxin genes were evaluated by a multiplex polymerase chain reaction. The strains were identified as EAEC with an optical density at 570 nm (OD 570 ) > 0.2. Results: Of the total 100 Escherichia coli strains, 28 were positive by Polymerase Chain Reaction for two genes, AggR and EAST. Of the 28 PCR-positive strains screened for biofilm, 25 (89.2%) showed positive results by microtiter plate method. Conclusion: The quantitative biofilm assay using microtiter plate is convenient and economical and can be used as a screening method to screen E. coli isolates from acute diarrheal cases. The best use of this test is to screen large number of isolates quickly, and if positive this can be confirmed by multiplex PCR for AggR and EAST genes. This assay may contribute to demonstrating the true incidence of EAEC with and without AggR among clinically isolated E. coli strains, which can cause acute diarrhea.Item Induction of resistance to fluoroquinolones in clinical and environmental isolates of Pseudomonas aeruginosa.(2007-01-04) Prasad, S Vishnu; Ballal, Mamatha; Shivananda, P GAn attempt to induce resistance to ciprofloxacin in vitro was made against clinical and environmental isolates of Pseudomonas aeruginosa. This in vitro manipulation of strains resulted in the increase of minimum inhibitory concentration from 0.4 microg/ml to 1 microg/ml of the original strains to 9.0 to 12.5 microg/ml indicating development of resistance to ciprofloxacin and a major decrease in the size of zone diameters of norfloxacin and ofloxacin indicating cross resistance to these agents. Results indicate the induced resistance to ciprofloxacin can promote development of cross resistance to other fluoroquinolones. This suggests that caution should be taken while using fluoroquinolones for the treatment of Pseudomonas aeruginosa infections.Item Myristica fragrans [nutmeg] and its activity against the enteric pathogens.(2003-07-18) Ballal, Mamatha; Pradeep,; Shivananda, P GItem Paraffin baiting system for demonstration of growth and biofilm production in Pseudomonas aeruginosa.(2007-03-22) Vishnu Prasad, S; Ballal, Mamatha; Shivananda, P GPseudomonas aeruginosa is one of the commonest pathogens among the pseudomonads. This organism can grow in minimal nutritional requirements. Because of the ability of pseudomonads to grow on paraffin is not commonly found among other human pathogens and the primary human pathogen being P. aeruginosa, we studied the adaptation of this organism to paraffin baiting system for growth and biofilm formation. Strains were tested for the capacity to use paraffin as the sole source of carbon using Czapek's minimal salt medium. Of the 53 clinical isolates of P. aeruginosa, 20 strains exhibited growth by 24 hrs and 42 strains by 48 hrs. The remaining strains did not show any growth in the paraffin baiting system. The oxidase test with the paraffin baiting system was also performed. This simple and inexpensive method can be used to isolate and demonstrate the biochemical and biofilm forming capacity of the organism.Item Rotavirus and enteric pathogens in infantile diarrhoea in Manipal, South India.(2002-05-14) Ballal, Mamatha; Shivananda, P GThe etiology of Rotavirus in acute diarrhoeal illness in children 0-5 years of age, admitted to the pediatric wards of Kasturba Medical College Hospital, Manipal was studied over a period of 5 years. Rotavirus in the faeces detected by Latex agglutination test accounted for 19.56% of the diarrhoea with maximum incidence (65%) in the 7-12 months of age group. Bacterial aetiological agents continued to play a significant role (69.6%) in diarrhoeal diseases. Enteroaggregative E. coli was common in the age group between 25-36 months, Shigellosis in 37-60 months and Salmonella typhimurium enteritis in 7-12 months of age. The other pathogens isolated were vibrio cholerae (4.98%), species of aeromonas (15.92%), along with cryptosporidium (6.47%) and candida albicans (3.98%). In a control group consisting of 100 children without history of diarrhoea, 2 were positive for rotavirus, 3 for cryptosporidium and 12 for Escherichia coli.Item Slime production a virulence marker in Pseudomonas aeruginosa strains isolated from clinical and environmental specimens: a comparative study of two methods.(2009-04-01) Prasad, S Vishnu; Ballal, Mamatha; Shivananda, P GDetection of slime in Pseudomonas aeruginosa can be useful in understanding the virulence of this organism. Here, comparative studies of two phenotypic methods using the tube method and the spectrophotometric method for slime production from 100 clinically and 21 environmentally significant isolates of P. aeruginosa were performed. A total of 68 isolates were positive by either of the tests whereas only 34 were positive by both the tests. The tube method detected slime significantly in more number of isolates than the spectrophotometric method. The tube test was found to be superior to the spectrophotometric method in ease of performance, interpretation and sensitivity. Among the clinical isolates, systemic isolates produce less slime compared to wound, respiratory and urinary isolates. Isolates from the hospital environment produced more slime indicating that this virulence marker helps the organism to survive for longer periods and cause nosocomial infections.