Frequency of Antibiotic Resistance among Bacteria Isolated From a High School Setting Katie Amato Columbia High School Introduction The number of intestinal infections is approaching 100 million cases per year in the United States. Resistant bacterial strains often double hospital stay duration and mortality rates as compared to strains that can be treated. Introduction Antibiotic: a molecule used to kill microorganisms and treat bacterial infections nextnature.net itech.dickinson.edu Introduction Resistance can be caused by DNA transfer via plasmids, or environmental factors changing the DNA. A growing problem as the antibiotics we have are becoming less and less effective. Introduction Antibiotics work by targeting different parts of the bacteria cell and inhibiting proper function. If the antibiotic interferes with the synthesis of the cell wall, the bacteria will not reproduce, but will die. For example, the interaction of penicillin with penicillin-binding proteins. mrsatopic.com Review of Literature Mao, EF, et al. “Proliferation of mutators in a cell population.” Journal of Bacteriology (Jan. 1997): 417-422. Mutagens and mutations Giraud, Antione et al. “Mutator bacteria as a risk factor in treatment of infectious diseases.” Antimicrobial Agents and Chemotherapy (Mar. 2002): 863-865. Synergy treatment High concentration Review of Literature Andersson, Dan. “Persistence of antibiotic resistant bacteria.” Current Opinion in Microbiology 6 (2003): 452-456. Fitness cost Levy, Stuart B., and Marshall, Bonnie. “Antibacterial resistance worldwide: causes, challenges and responses.” Nature Medicine Supplement 10 (Dec. 2004): 122-129. Global problem Economic costs Hypothesis The majority of the bacteria found in this high school setting will not express antibiotic resistance. Methods Wet a sterile swab with sterile distilled water. Thoroughly swab selected surface with the wetted swab and streak over a 5% Sheep’s blood agar plate. Place plates in a 37° incubator overnight, or until colony growth appears. Inoculated Control Methods After colony growth appears, isolate specific colonies off of the initial plate. Use a sterile loop to pick up bacteria cells, and perform a three-point streak onto a different blood agar plate for each colony to be examined further. Permanent stocks of cultures need to be made using a glycerol solution. biology.clc.uc.edu Methods Gram staining will be used to determine whether the bacterium is Gram positive or Gram negative. Further testing methods will depend on the Gram result. student.ccbcmd.edu Mesacc.edu Bd.com Methods Samples are to be tested for antibiotic sensitivity and/or resistance by exposure to different antibiotics (Kirby-Bauer Assay). blogs.nature.com Results—Plate 1 Sample 1-3 was found to be Gram+ cocci, catalase positive, and mannitol fermentation negative. 1-3 Results—Plates 2 and 3 Results—Plate 4 Sample 4-1 was found to be Gram- bacilli and oxidase negative, but has not yet been identified using an Enterotube. Results—Plate 6 6-1: Gram- bacilli, oxidase negative, yet to be Enterotube-d. 6-1 6-2: Gram- cocci, not yet identified 6-2 Results—Kirby Bauer Assay Discussion Varying amounts and types of bacteria were found on all tested surfaces. Samples need to be identified. 1-3, 6-1, and 6-2 are sensitive to the tested antibiotics. Conclusion Of the bacteria that consistently grew in fresh culture, no resistance was found for the tested antibiotics. The identity of the various bacterial samples remains unknown. Future Research Test more antibiotics Collect more samples Best results would be obtained from freshly grown cultures. Acknowledgements Dr. Ann Zeeh Ms. Gleason and Ms. Strauss Ms. Masiello, Mr. Fudge, Mrs. Prout Science Research students My parents References Andersson, Dan. “Persistence of antibiotic resistant bacteria.” Current Opinion in Microbiology 6 (2003): 452-456. Giraud, Antione et al. “Mutator bacteria as a risk factor in treatment of infectious diseases.” Antimicrobial Agents and Chemotherapy (Mar. 2002): 863-865. Klugman, Keith, et al. “Bactericidal activity against cephalosporin-resistant Streptococcus pneumoniae in cerebrospinal fluid of children with acute bacterial meningitis.” Antimicrobial Agents and Chemotherapy 39 (6 Jul. 1995): 1988-1992. Levy, Stuart B., and Marshall, Bonnie. “Antibacterial resistance worldwide: causes, challenges and responses.” Nature Medicine Supplement 10 (Dec. 2004): 122-129. Mao, EF, et al. “Proliferation of mutators in a cell population.” Journal of Bacteriology (Jan. 1997): 417-422. Paris, Maria, et al. “Management of meningitis caused by penicillin-resistant Streptococcus pneumoniae.” American Society for Microbiology 39.10 (1995): 21712175. Sandora, Thomas, et al. “Reducing asenteeism from gastrointestinal and respiratory illness in elemntary school students: a randomized, controlled trial of an infectioncontrol intervention.” Pediatrics 2008; 121; e1555. DOI: 10.1542/peds.2007-2597. Questions?