This document summarizes an experiment that tested the minimum inhibitory concentrations (MICs) of antibiotics against Neisseria gonorrhoeae strains isolated from different anatomical sites within patients. The results showed significant differences in MICs among strains from different sites in the same patient, suggesting that the human body imparts selective pressure that influences antibiotic treatment effectiveness for gonorrhea infections in different locations. Further research is needed to understand the genetic mechanisms underlying these observed differences in antibiotic resistance among strains from different infection sites.

1. Strains:
• Strains MS11Δopa (strain A) and MS11opak (strain B) were
used as controls. Multiple isolated disseminated gonococcal
strains were tested.
• GC strains were grown on GCK plates and incubated for 24
hours to prep. Standard temperature was controlled at 37° C
with 5% CO2 levels.
Media Making:
• The GCK plate mixture involved agar, GC medium, and DI
water. Antibiotics tested were Erythromycin,
Spectinomycin, Ciprofloxacin, Chloramphenicol, and
Kanamycin.
MIC Test:
• Serial dilutions were used to create varied concentrations of
N. Gonorrhoea
Presented by:Neisseria gonorrhoeae from different anatomical locations in
the same patient exhibits different MICs
20
25
1 0.004 1
20
12.5
1 0.0025 1
ConcentrationAntibiotic(ul)
Patient 29 MIC
29U 29B
15
12.5
1 0.02 1
20
12.5
1 0.02 1
ConcentrationAntibiotic(ul)
Patient 61 MIC
61B 61C
Abstract
Neisseria gonorrhoeae (GC), responsible for the sexually transmitted infection gonorrhea, can infect the reproductive tract of women, and if left untreated, can lead to pelvic inflammatory disease (PID), infertility, and increase the risk of ectopic
pregnancy. It can also lead to disseminated gonococcal infection and gonococcal arthritis. The CDC estimates that GC infections cause at least 24,000 women in the US to become infertile each year, with the estimated cost of diagnosis and treatment
exceeding $5 billion per year. This is likely to underestimate the true cost of disease. Gonorrhea is currently treated with antibiotics.
However, the recent emergence of antibiotic-resistant GC raises new concerns for controlling its infection, because once widely-recommended first-line antibiotics for gonorrhea are losing effectiveness around the world. While numerous studies have
examined the mechanisms of antibiotic resistance of GC, there are few reports studying how, under physiological conditions and in different infection sites, antibiotic resistance contributes to the fitness of bacterium. We hypothesize that GC have different
effective minimum inhibitory concentrations (MICs) in different infection sites.
To address this hypothesis, The FIRE AR stream examined the MICs of GC strains which were obtained from different anatomical locations. Our results identified significant differences in MIC among GC isolates from different sites in the same
patient. This suggests that the human body imparts selective pressure and plays a role in the effectiveness of antibiotic treatment in GC infections. This stream seeks to understand the underlying genetic mechanisms associated with this observation.
20
12.5
1 0.004 1
25
12.5
1 0.004 1
ConcentrationAntibiotic(ul)
Patient 21 MIC
21B 21C
Of the strains tested, most show a low to moderate-level resistance towards most antibiotics. In regards to Spectinomycin, the cervical
(23C) strains demonstrate a moderate-level resistance (average MIC of 28.75). Cervical strains also displayed exceptional resistance to
Kanamycin and Ciprofloxacin. The highest-level resistant strain of those tested is 23C, exhibiting relatively high resistance to both
Spectinomycin, Kanamycin, Ciprofloxacin, and Chloramphenicol. Other notable strains are rectal (54R), and throat (48T) strains. Throat strains
exhibited a dark yellow color not seen in other strains, possibly due to their unique growth environment.
References:
Unemo, M., Golparian, D., Nicholas, R., Ohnishi, M., Gallay, A., & Sednaoui, P. (2011). High-Level Cefixime- and Ceftriaxone-Resistant
Neisseria gonorrhoeae in France: Novel penA Mosaic Allele in a Successful International Clone Causes Treatment Failure. <i>Antimicrobial
Agents And Chemotherapy,</i> <i>5</i>(50), 1273-1280.
Strain Spectinomycin Kanamycin Erythromycin Ciprofloxacin Chloramphenicol
21B 20 12.5 1 0.004 1
21C 25 12.5 1 0.004 1
23B 25 12.5 1 0.004 1
23C 50 25 1 0.004 4
29B 20 12.5 1 0.0025 1
29U 20 25 1 0.004 1
61B 15 12.5 1 0.002 1
61C 20 12.5 1 0.002 1
61J 20 12.5 2 0.002 1
25
12.5
1 0.004 1
50
25
1 0.004 4
ConcentrationAntibiotic(ul)
Patient 23 MIC
23B 23C
20
12.5
1 0.004 1
25
12.5
1
0.004
1
20
12.5
1 0.0025 1
15
12.5
1
0.02
1
Spectinomycin Kanamycin Erythromycin Ciprofloxacin Chloramphenicol
ConcentrationAntibiotic(ul)
Blood Bacterial Strain Relationship
21B 23B 29B 61B
25
12.5
1 0.004 1
50
25
1
0.004
4
20
25
1 0.0025 1
20
12.5
1
0.02
1
Spectinomycin Kanamycin Erythromycin Ciprofloxacin Chloramphenicol
ConcentrationAntibiotic(ul)
Cervical Bacterial Strain Relationship
21C 23C 26C 61C
Methods
Data
Figure 1.0 - Columns are labelled A, 48T1,
and B consecutively with a name and date.
Dilutions were created at 107/ml GC, 105,
1/3 x 105/ml GC, 1/9 x 105/ml GC, 1/27 x
105/ml GC, 1/81 x 105/ml GC, and 1/243 x
105/ml GC
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