Experimental Human Infection With Neisseria Gonorrhoeae

Study Overview
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Brief Summary
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This is a Phase 1, interventional, non-randomized, experimental infection model study with healthy adult males adults (N=32) between the ages of 18-36 at study enrollment. The study is designed to test the requirements of predicted N. gonorrhoeae virulence determinants for gonococcal infection in the male urethra. The duration for all participants will be about 3 weeks. Study duration will be approximately about 18 months for implementation and enrollment. The primary objectives of the present study are to: (1) compare infectivity of different isogenic mutants with wild-type (WT) N. gonorrhoeae in noncompetitive infections and to (2) assess relative fitness of the mutant in competitive infections initiated by inocula containing equivalent numbers of both WT and mutant strains for mutants with WT infectivity.

Detailed Description
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This is a Phase 1, interventional, non-randomized, experimental infection model study with healthy adult males adults (N=32) between the ages of 18-36 at study enrollment. The study is designed to test the requirements of predicted N. gonorrhoeae virulence determinants for gonococcal infection in the male urethra. For each mutant to be investigated under this protocol, groups of subjects will be enrolled first in noncompetitive infection studies: Group 1 (n = up to 8) will receive a bacterial inoculum containing only the isogenic mutant N. gonorrhoeae strain, and Group 2 (n = up to 8) will receive a bacterial inoculum containing only the wild-type (WT) N. gonorrhoeae strain. If primary and secondary outcomes are not different for the isogenic mutant and WT strains, a group of subjects will be enrolled in competitive infection studies: Group 3 (up to 16) will receive a bacterial inoculum containing a mixture of equivalent numbers the isogenic mutant and WT strain. All subjects will be examined daily for symptoms of infection and receive antibiotic treatment at the end of the inpatient portion of the trial. Within 7 days of antibiotic treatment, subjects will return for a follow-up examination. A final follow-up phone interview will be conducted within 2 weeks of antibiotic treatment. The duration for all participants will be about 3 weeks. Study duration will be approximately about 18 months for implementation and enrollment. The primary objectives of the present study are to: (1) compare infectivity of different isogenic mutants with wild-type (WT) N. gonorrhoeae in noncompetitive infections and to (2) assess relative fitness of the mutant in competitive infections initiated by inocula containing equivalent numbers of both WT and mutant strains for mutants with WT infectivity. Note, competitive infections will not be performed if non-competitive infections are substantially different. If this is the case, there will be no analysis for this primary objective. The study secondary objective is to compare the clinical course of infection with mutant and WT N. gonorrhoeae in noncompetitive infections.

Official Title
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Experimental Human Infection With Isogenic Mutants of Neisseria Gonorrhoeae

Conditions
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Gonococcal Infection

Intervention / Treatment
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* Drug: Cefixime
* Drug: Ceftriaxone
* Drug: Ciprofloxacin
* Biological: Neisseria gonorrhoeae strain FA1090 A26
* Biological: Neisseria gonorrhoeae strain FA7537


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy man > / = 18 and < 36 years old Able and willing to be located easily by providing street address and telephone number (land line and/or cell phone number) Willingness to provide written informed consent Able and willing to attend all study visits including 6-day stay in the Clinical Translational Research Center (CTRC) during the trial (with ability to leave the unit during the day) and follow-up visit during the week after treatment Able and willing to abstain from all sexual activity until completion of the study and the follow-up test for gonorrhea is negative Acceptable medical history by screening evaluation No clinically significant abnormalities on physical exam Urinalysis: leukocyte esterase, and White Blood Cell (WBC) values within normal limits (WNL) CH50 WNL Urine negative for chlamydia, gonorrhea, and trichomonas Negative Human Immunodeficiency Virus (HIV), syphilis, and Hepatitis C (HCV) test results Negative Hepatitis B (HBV) core and surface antibodies or results consistent with immunization (negative HBV core antibody/positive HBV surface antibody) Denies history of Sexually Transmitted Infections (STIs) including gonorrhea, chlamydia, syphilis, HIV, HBV, and HCV Denies history of bleeding diathesis Denies history of seizures (due to reports of seizures with ciprofloxacin) Denies history of cancer, except basal cell carcinoma of the skin > 5 years ago Denies history of drug abuse Denies history of genitourinary surgery Exclusion Criteria: Student or employee under the direct supervision of any of the study investigators Any known immunodeficiencies including complement deficiency, antibody deficiency, chronic granulomatous disease or Human Immunodeficiency Virus (HIV) infection Psychiatric disorders that, in the opinion of the physician, would interfere with the integrity of the data or volunteer safety Unstable depression (defined as receiving either < 3 months of the same medication (and dose) or a decompensating event during the previous 3 months) or depression that, in the opinion of the investigator, will compromise the subject's ability to comply with protocol requirements Heart murmur or heart disease Anatomic abnormality of the urinary tract Any antibiotic treatment in the past 30 days, or azithromycin in the past 60 days Self-reported chemotherapy within the past year Current steroid use, except for topical application Allergy to penicillin, cephalosporins or ciprofloxacin or to lidocaine Treatment with medications in the previous month that are contraindicated with cefixime, ceftriaxone or ciprofloxacin and that cannot be withheld for the single doses given in this study Serum creatinine level < 0.7 or > 1.75 mg/dL and deemed clinically significant by the study physician Serum ALT level < LLN or > 105 U/L and deemed clinically significant by the study physician WBC count < 2.5 or > 15.0 x 10^9/L and deemed clinically significant by the study physician Absolute neutrophil count (ANC) < 1.5 or > 7.5 x 10^9/L and deemed clinically significant by the study physician Exception: For African Americans, ANC values as low as 1.3 x 10^9/L will be allowed (25) Hemoglobin level < 12.0 g/dL or above ULN and deemed clinically significant by the study physician Urinalysis: Qualitative protein level > 1+ or RBC count > 10/hpf Medications not permitted with cefixime or ceftriaxone: Warfarin Probenecid Aspirin Diuretics such as furosemide Aminoglycoside antibiotics Chloramphenicol Medications not permitted with ciprofloxacin: Tizanidine Theophylline Warfarin Glyburide Cyclosporine Probenecid Phenytoin Methotrexate Antacids, multivitamins, and other dietary supplements containing magnesium, calcium, aluminum, iron or zinc Caffeine-containing medications Sucralfate or didanosine chewable or buffered tablets

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 36 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group 1<br>Subjects (n = up to 8) will receive a bacterial inoculum containing only the isogenic mutant N. gonorrhoeae strain | Drug: Cefixime<br>* Mandatory rescue therapy consisting of cefixime 400 mg orally in a single dose: on patient request, at the onset of symptoms or on the 5th study day after inoculation.<br>Drug: Ceftriaxone<br>* Mandatory rescue therapy consisting of ceftriaxone 250 mg intramuscularly in a single dose: on patient request, at the onset of symptoms or on the 5th study day after inoculation.<br>Drug: Ciprofloxacin<br>* Mandatory antibiotic treatment failure therapy: Ciprofloxacin 500 mg orally in a single dose: if the subject has a positie test of cure 1 week post initial antibiotic treatment<br>Biological: Neisseria gonorrhoeae strain FA7537<br>* 0.4 mL of a suspension containing 10^5 - 10^6 CFU of Neisseria gonorrhoeae, in phosphate-buffered saline, delivered to the anterior urethra through a No.8 pediatric French catheter<br>|
| Experimental: Group 2<br>Subjects (n = up to 8) will receive a bacterial inoculum containing only the wild-type (WT) N. gonorrhoeae strain. | Drug: Cefixime<br>* Mandatory rescue therapy consisting of cefixime 400 mg orally in a single dose: on patient request, at the onset of symptoms or on the 5th study day after inoculation.<br>Drug: Ceftriaxone<br>* Mandatory rescue therapy consisting of ceftriaxone 250 mg intramuscularly in a single dose: on patient request, at the onset of symptoms or on the 5th study day after inoculation.<br>Drug: Ciprofloxacin<br>* Mandatory antibiotic treatment failure therapy: Ciprofloxacin 500 mg orally in a single dose: if the subject has a positie test of cure 1 week post initial antibiotic treatment<br>Biological: Neisseria gonorrhoeae strain FA1090 A26<br>* 0.4 mL of a suspension containing 10^5 - 10^6 CFU of Neisseria gonorrhoeae, in phosphate-buffered saline, delivered to the anterior urethra through a No.8 pediatric French catheter.<br>|
| Experimental: Group 3<br>Subjects (n= up to 16) will receive a bacterial inoculum containing a mixture of equivalent numbers the isogenic mutant and WT strain | Drug: Cefixime<br>* Mandatory rescue therapy consisting of cefixime 400 mg orally in a single dose: on patient request, at the onset of symptoms or on the 5th study day after inoculation.<br>Drug: Ceftriaxone<br>* Mandatory rescue therapy consisting of ceftriaxone 250 mg intramuscularly in a single dose: on patient request, at the onset of symptoms or on the 5th study day after inoculation.<br>Drug: Ciprofloxacin<br>* Mandatory antibiotic treatment failure therapy: Ciprofloxacin 500 mg orally in a single dose: if the subject has a positie test of cure 1 week post initial antibiotic treatment<br>Biological: Neisseria gonorrhoeae strain FA1090 A26<br>* 0.4 mL of a suspension containing 10^5 - 10^6 CFU of Neisseria gonorrhoeae, in phosphate-buffered saline, delivered to the anterior urethra through a No.8 pediatric French catheter.<br>Biological: Neisseria gonorrhoeae strain FA7537<br>* 0.4 mL of a suspension containing 10^5 - 10^6 CFU of Neisseria gonorrhoeae, in phosphate-buffered saline, delivered to the anterior urethra through a No.8 pediatric French catheter<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Competitive Index of the Mutant Compared to Wild Type Proportion of Organisms With the Predicted Competitive Advantage Recovered From Urine and/or Urethral Swab Specimens From Infected Participants | The competitive index (CI) is defined by the ratio of colony forming units (cfu) of the two strains recovered from urine cultures on the day of treatment (output) compared to the ratio of strains in the inoculum (input): CI = mutant cfu(output)/wild-type cfu(output) ÷ mutant cfu(input)/wild-type cfu(input). The CI is used to assess whether the fitness of a given mutant is different than that of wild-type, and CI as a ratio is compared to 1. If it's not significantly different than 1, then no significant difference in the fitness was observed. Mutant or wild-type cfu values of 0 were replaced by 1 in the calculation of competitive index. The assessment was performed in the MtrD trial mixed group. | Baseline and the day of treatment, any day between Day 2 and Day 6 | 
| Proportion of Participants That Become Infected as Defined by a Positive Urine or Urethral Swab Culture Among Infections Initiated With Individual N. Gonorrhoeae Strains in Non-competitive Infections | Infection is defined by a positive urine or urethral swab culture. The proportion of infected participants by Day 6 with N. gonorrhoeae was assessed in each trial by group among participants with non-competitive infections. Participants could become infected and received treatment any day before or on day 6. | day of infection, any day between Day 2 and Day 6 | 
| Proportion of Participants That Become Infected as Defined by a Positive Urine or Urethral Swab Culture for Infections Initiated With Mixed Inocula | Infection is defined by a positive urine or urethral swab culture. The proportion of infected participants by Day 6 with N. gonorrhoeae was assessed in each trial among participants with infections initiated with mixed inocula. Participants could become infected and received treatment any day before or on day 6. | day of infection, any day between Day 2 and Day 6 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Median Time From Inoculation to Treatment Among Infected Participants by Day 6, by Strain, in Non-competitive Infections | The median time from inoculation to antibiotic treatment were calculated for each group. | Day 2 through the day of treatment, up to Day 6 | 
| Proportion of Participants With Occurrence of Bacteriuria in Non-competitive Infections, by Strain | Bacteriuria is defined as Log10 cfu N. gonorrhoeae/mL urine sediment. | Day of occurrence, any day between Day 2 and Day 6 | 
| Proportion of Participants With Occurrence of Signs and Symptoms of Urethritis Attributable to Gonococcal Infection in Non-competitive Infections, by Strain | Participants with any subjective symptoms or objective signs (observed urethral discharge) during period 01 (post-inoculation and before treatment which can occur on or before day 6) from the Solicited Events Form were captured. | Day of occurrence, any day between Day 2 and Day 6 | 
| Proportion of Participants With Occurrence of Urethritis in Non-competitive Infections | Urethritis is defined as >= 5.8 Log10 WBC/mL urine sediment. | Day of occurrence, any day between Day 2 and Day 6 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ceftriaxone, challenge, ciprofloxacin, males, Neisseria gonorrhoeae