Transcript Frequency of Antibiotic Resistance among Bacteria Isolated From a High School Setting Katie Amato Columbia High School.

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
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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.
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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.
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Methods

Samples are to be tested for antibiotic
sensitivity and/or resistance by exposure
to different antibiotics
(Kirby-Bauer Assay).
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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?