Syphilis. -Spiral shaped spirochete (Treponema pallidum) -gram negative, but does not have lipopolysaccharide (LPS) -helical, thin (0.1 to 0.2 um), and long -flagella are inserted into the periplasm and give it motility -sensitive to drying, chemicals, and heat (as low as 42 degrees celsius).
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-gram negative, but does not have lipopolysaccharide (LPS)
-helical, thin (0.1 to 0.2 um), and long
-flagella are inserted into the periplasm and give it motility
-sensitive to drying, chemicals, and heat (as low as 42 degrees celsius)Bacteriology of Syphilis
How common?3rd most common STD
2006: > 36,000 cases of syphilis
Incidence of 1° & 2° syphilis highest in women aged 20-24 and men aged 35-39
2008: 63% of 1° & 2° syphilis infections involved MSM
2004-2008: syphilis rates increased greatest among men & women 15-24 y/o
How do we spread it?Sexual contact: vaginal, oral, or anal
Spreads P-to-P via direct contact with a sore
Sore locations: external genitals, vagina, anus, rectum, lips, & mouth
Also, congenital infxn via transplacental transmission
Usually any time >20wks gestation
Spirochetes are capable of crossing placenta
The culprit?Treponema pallidum
NOT transmitted through contact with:
Hot tubs or bathtubs
Primary Syphillis presents with a
-pleomorphic and non-motile
-small in size (0.25 to 0.8 um in diameter), and have small chromosomes (1 – 1.2 megabases)
-”Energy Parasites”: Auxotropic for amino acids, and use host cell’s ATP
-Cell wall is unusual in that it lacks muramic acid
-Cannot be cultured in nutrient broth media or on agar platesBacteriology of Chlamydia
How common?#1 reported STD in U.S.
Highest infxn rates in Native & African Americans
2010: 1,307,893 reported infxns from 50 states
Many unreported cases d/t lack of sxs in many individuals
An estimated 2.8 million infxns occur in U.S. per year
Worldwide, an estimated 90 million new cases each year
Esp high infxn risk for sexually active teen girls d/t immaturity of cervix being more susceptible to infxn
How do I get it?Vaginal, oral, or anal sex
Also transmitted during childbirth
More sexual partners = higher risk
Urethra = most common site for infxn in both men & women
Chlamydia trachomatis = MCC of acute urethral syndrome in women & MCC of nonspecific urethritis (NSU) in men
The leading preventable cause of infertility worldwide
N. gonorrhoeae coexists in 45% of cases
http://www.sharinginhealth.ca/images/Chlamydia_trachomatis_speculum_SOA_Amsterdam.jpg & http://www.mdguidelines.com/images/Illustrations/pel_in_d.jpg
-humans are the only reservoir
-Ferment glucose, but do not ferment maltose
-No polysaccharide capsule
-produce IgA proteasesBacteriology for N. Gonorrhea
How common? 2nd most common venereal disease
2009: 301,174 reported cases
However, in U.S., it's estimated that >700,000 new infxns occur each year
Highest rates in sexually active teens, young adults, MSM, Hispanics & AAs
Worldwide, an estimated 62 million new cases each year
W/highest rates in sub-Saharan Africa, southeast Asia, the Caribbean, & Latin America
How are we spreading it?Contact w/infected penis, vagina, mouth, or anus
Pregnant female can transmit infxn to baby during delivery as well
Bacteria multiplies easily in warm, moist areas
Urethra = MC site for gonococcal infxn in both men & women
N. gonorrhoeae = MCC of septic arthritis in urban populations
Can lead to disseminated gonococcemia
More common in young women d/t C6-C9 deficiency
Q1: A 32y/o businessman comes into your office. He was well until yesterday, when he admits he experienced dysuria accompanied by yellowish urethral discharge. He also admits that he had intercourse with a prostitute 5 nights ago. You perform a gram stain on a specimen of the discharge and see gram-negative diplococci within neutrophils. Given this characteristic finding, you know right away that the most likely cause of this infection is?
Q2: A 30-year-old, sexually active woman has had a mucopurulent vaginal discharge for 1 week. On pelvic examination, the cervix appears reddened around the os, but no erosions or mass lesions are present. A Pap smear shows numerous neutrophils, but no dysplastic cells. A cervical biopsy specimen shows marked follicular cervicitis. Which of the following infectious agents is most likely to produce these findings?
Q3: A 73-year-old man who has had progressive dementia for the past 6 years dies of bronchopneumonia. Autopsy shows that the thoracic aorta has a dilated root and arch, giving the intimal surface a “tree-bark” appearance. Microscopic examination of the aorta shows an obliterative endarteritis of the vasa vasorum. Which of the following laboratory findings is most likely to be recorded in this patient's medicalhistory?
Q4: A sexually active, 26-year-old man has had pain on urination for the past 4 days. On physical examination, there are no lesions on the penis. He is afebrile. Urinalysis shows no blood, ketones, protein, or glucose. Microscopic examination of the urine shows few WBCs and no casts or crystals. What infectious agent is most likely to produce these findings?
Q5: A 20-year-old man who has multiple sexual partners and does not use barrier precautions comes to the physician complaining of a nontender ulcer on the penis that has been present for 1 week. On physical examination, the 0.6-cm lesion has a firm, erythematous base and sharply demarcated borders. The lesion is scraped, and darkfield examination is positive for spirochetes consistent with Treponema pallidum. Which of the following is most likely to be seen microscopically in the biopsy specimen?