Urogenital Tract Infections Medical Microbiology By: Clark McLaughlin Powerpoint adapted from Nikhil Shah November 2017 • Urinary Tract Infections • Vaginitis • Cervicitis • Pelvic Inflammatory Disease • Urethritis • Genital ulcers • Prostatitis Risk Factors for Infection • Pregnancy • Diabetes (elevated glucose) • Urethra length (higher incidence in females) • Obstruction or decreased clearance (stone formation) • Catheterization • Frequent or recent intercourse • Antibiotics • Previous UTIs and Retrovesicular movement Upper vs. Lower UTIs • Cystitis (Lower) • Frequency • Urgency • Burning • Dysuria • Suprapubic pain • Pyelonephritis (Upper) • Cystitis Symptoms + • Fever • Chills • Nausea / Vomiting • Hypotension • Costovertebral angle pain UPEC vs. Klebsiella vs. Proteus(All gram neg) • UPEC • Non-encapsulated • IBCforming(biofilm) • Lactose fermenting • Glucosefermenting • Catalase (+) • Klebsiella • Encapsulated • Carbapenemresistance • Lactose fermentation • Proteus vulgaris • Phenylalanine deaminase • Swarming motility (concentric circles when plated) • H2S production • Urease (+) • Alkanization of urine Struvite(MgNH4PO 4) formation Pathogenesis of E. Coli in Cystitis and Pyelonephritis • 1) Contamination of peri-urethral area with UPEC from gut • 2) Colonization of urethra and bladder: pili & adhesins • Type 1 Fimbrae: mannose-sensitive can’t ascend cystitis • P-Fimbrae: not weakened by mannose exposure can ascend Pyelonephritis • • • • • • • • 3) Migration to bladder: motility 4) Colonization of bladder intracellular biofilm communities 5) Inflammation: LPS immune system proliferation 6) Biofilm Formation(with use of Quorum Sensing) 7) Epithelial Damage: via bacterial toxins and proteases 8) Ascend to kidneys(P-Fimbrae) 9) Colonization of kidneys 10) Bacteremia Struvite Stone Formation in Proteus spp. • 1) Bacterial adhesion in kidney • 2) Urease ammonia increased pH • 3) Multiple micro-colony formation • 4) Secretion of polysaccharide • 5) Crystal formation within polysaccharide • 6) Micro-colonies adhere to each other via crystals • 7) Cycle repeats to form ‘staghorn’ stone Staphylococcus saprophyticus • Young Sexually active females (BUT REMEMBER E. COLI is more common! You must have labs saying Gram + cocci is found) • Gram (+) cocci • Non-hemolytic on blood agar • Coagulase (-) Catalase (+) • Negative nitrates • Resistant to novobiocin Interpretation of Urinalysis Component Normal Range Indicator of infection Leukocyte esterase 0 Positive = pyuria presence of WBCs Nitrite 0 Positive = presence of bacteria that reduce nitrate (except S. Saprophyticus) WBC <5 WBC>10 = pyuria RBC <5 RBC>5 = Hematuria Epithelial Cells <5 Indicated a good sample pH 4.5 – 8 Elevated if urea-splitting bacteria present Infections of the Pelvic Area Syndrome Main Pathogens Less Common Vaginitis Mixed bacterial Candida T. vaginalis Cervicitis C. trachomatis N. gonorrhea Pelvic Inflammatory Disease Polymicrobial N. gonorrhea C. trachomatis Urethritis N. gonorrhea C. trachomatis M. genitalium T. vaginalis Genital Ulcers HSV-2 T. pallidum H. ducreyi C. trachomatis K. granulomatis Prostatitis Gram (-) rods N. gonorrhea C. trachomatis HSV T. vaginalis • Urinary Tract Infections • Vaginitis • Cervicitis • Pelvic Inflammatory Disease • Urethritis • Genital ulcers • Prostatitis Polymicrobial (Bacterial) Vaginitis • ETIOLOGY: endogenous bacterial overgrowth • • • • Haemophilus spp. Gardnerella vaginalis Bacteroides spp. Decrease in lactobacilli (increased pH) • PATHOGENESIS: • • • • • Mucin/cell-degrading enzymes (collagenase, sialidase, fibrinolysins) Hemolysins release nutrients IgA protease reduces host immunity Urease cytotoxicity of ammonia Amines increase pH • DIAGNOSIS: Nugent Score (wet mount and gram stain) or Amsel Criteria (¾ of the following…) • • • • (1) pH >4.5 (2) >20%/HPF of clue cells (epithelial cells covered with bacteria) (3) positive whiff test (sniff sniff…. Mmmmm) (4) homogenous, non-viscous, milky white discharge • SYMPTOMS: mostly asymptomatic • Malodorous (fishy smelling) discharge (more commonly after intercourse or menses) Vulvovaginal Candidiasis • PATHOGENESIS: • • • • • Adhesins (Als3) Directional hyphal growth (contact sensing) Dimorphism Biofilm formation Iron acquisition (siderophore) • SYMPTOMS: vulvar pruritis • Thick, white, curdy vaginal discharge (cottage-cheese like) • Erythematous ‘satellite’ lesion • DIAGNOSIS: 10% KOH to find pseudohyphae w/ budding, Germ tubes • pH should be normal Sexually Transmitted Diseases Trichomonas Vaginalis • ETIOLOGY: only protozoan parasite that infects the genital tract • MORPHOLOGY: 4 flagella + undulating membrane trophozoite(the only form this has), no mitochondria • SYMPTOMS: frothy gray/yellow-green vaginal discharge • Pruritis • Cervical petechia (strawberry cervix) • May infect Skene’s glands • DIAGNOSIS: modified Diamond’s Media (gold standard) • Increased vaginal pH • Whiff test (+) • Urinary Tract Infections • Vaginitis • Cervicitis • Pelvic Inflammatory Disease • Urethritis • Genital ulcers • Prostatitis Neisseria gonorrhea Neisseria gonorrhea • CLASS: Gram (-) diplococci, intracellular, no capsule, oxidase (+) • PATHOGENESIS: • • • • Type IV Pili (pilE): adhesion IgA1 protease: inactivation of IgA Opa, Opc, porin: adhesion, invasion, iron uptake LOS (instead of LPS): absence of O-antigen, triggers cytokine production • SYMPTOMS: • • • • Male: white, yellow/green discharge, painful urination, testicular swelling Women: vaginal discharge, painful urination, painful intercourse, metrorrhagia Neonatal: conjunctivitis Disseminated: dermatitis, endocarditis, meningitis, tenosynovitis • DIAGNOSIS: Thayer-Martin agar(Which is just chocolate agar with antibiotics selective for N. gonorrhea) in 10% CO2 • Gram smear sufficient for men • Culture required for women (N.gonorrhea as normal vaginal flora) • Urinary Tract Infections • Vaginitis • Cervicitis • Pelvic Inflammatory Disease • Urethritis • Genital ulcers • Prostatitis Chlamydia trachomatis Chlamydia trachomatis • LIFE CYCLE: infectious Elementary Bodies mitotic Reticulate Bodies EB exocytosis • SYMPTOMS: • Males: penile discharge, burning urination, itching of tip of penis • Females: abnormal discharge, dyspareunia, burning urination • Complications: endometritis, salpingitis, abscess, peritonitis, reactive arthritis • Fitz-Hugh-Curtis Syndrome (perihepatitis) • DIAGNOSIS: collection of columnar or cuboidal epithelial cells via urethral or cervical swabs (cell culture = gold standard) • Nucleic Acid Amplification Tests (NAATs) Lymphogranuloma venereum (LGV) • ETIOLOGY: invasive C. trachomatis strains L1,2,3 infection • SYMPTOMS: painful buboes in inguinal lymph nodes with systemic symptoms • Males: lesions at site of infection, fever/malaise/nausea, enlarged tender lymph nodes • Females: lesions at site of infection, rectal infection • Diagnosis: Collect epithelial cells, PCR • Urinary Tract Infections • Vaginitis • Cervicitis • Pelvic Inflammatory Disease • Urethritis • Genital ulcers • Prostatitis Herpes Simplex 2 Virus • ETIOLOGY: life-long chronic infection • Dormant in sacral ganglia (S2-S4): circularized genome latency transcript • Neurovirulence (HSV2) • Reactivation: fever, menstruation, sunlight, stress • PATHOGENESIS: • • • • • Glycoprotein-mediated binding to epithelial cells and keratinocytes Membrane fusion Early and late genes expressed Production of viral proteins and copies of genome Assembly and budding from cell cytolysis due to disruption of cytoskeleton • MORPHOLOGY: Cowdry type A intranuclear inclusions • Syncytia formation(Merging), Molding(nuclei condensed around circular circumference), Molding (nuclei form together) • SYMPTOMS: up to 80% asymptomatic • Primary: HSV1/2, tender painful vesicular ulcerative lesions, fever, headache, malaise, itching, dysuria, discharge, lymphadenopathy • Recurrent: HSV2 more common • CNS Complications: aseptic meningitis, HSV1 necrotizing encephalitis • DIAGNOSIS: microscopic examination Tzanck smear, Immunofluorescence or PCR Treponema Pallidum • CLASS: spirochete, no gram staining, burrowing motility, lacks TCA cycle, can grow in Armadillo feet • PATHOGENESIS: • Entry via minute lesions on skin and mucous membranes • Minimal species-specific antigens on surface (reduces immune efficacy) • Attaches to fibronectin and changes lipid membrane antigens daily=evasion! • TIMELINE: • Primary: 10-90 days, Secondary 14-30 days, Tertiary: years • DIAGNOSIS: • Darkfield and Fluorescent Treponemal Antibody (FTA-ABS) • VDRL (microscopic) and RPR (naked eye), cardiolipin-cholesterol lecithin antigen • Doesn’t grow an artificial media • SYMPTOMS: • Primary: painless hard chancre at site of infection • Secondary: rash (centrifugal including palms/soles), generalized lymphadenopathy, condylomata lata, alopecia • Late/Tertiary: 10-20 years after initial infection, (1) Gummatous lesions, (2) CV syphilis with aortic regurgitation (tree bark appearance due to endarteritis), (3) neurosyphilis • Latent: Early (initial infection <1 year ago) or Late (initial infection >1 year ago) • If untreated transmission to fetus up to 4 years after primary infection Hemophilus ducreyi • Organisms: Gram (-), pleomorphic coccobacillus aligned in chains • SYMPTOMS: ragged, painful soft chancroid (ulcer)(Because you “Do Cry “(Ducreyi) • Has CYTOLETHAL DISTENDING TOXIN and HEMOLYSIN • Tender regional lymphadenopathy • DIAGNOSIS: culture requires chocolate agar or blood agar with Factor X (hemin) • • • • • Gonococcal Agar base + 2% bovine hemoglobin + 5% fetal calf serum Mueller-Hinton agar with 5% heated horse blood Diagnosis based on ulcer appearance Rule out T. pallidum (darkfield microscopy) Rule out HSV (PCR negative) Mycoplasma genitalium • ETIOLOGY: triple layer external membrane contains sterol cholesterol(or serum) must be added to growth media(organisms do not grow on conventional agar!) • Free living • Self-replicating • PATHOGENESIS: • • • • • Adhesion via MgPa tip adhesins Evasion of host defenses via variable surface lipoproteins H2O2 and superoxides Inflammatory cytokines, immune cell stimulation/suppression Tissue damage Klebsiella granulomatis • CLASS: gram (-) enterobacteriacea, encapsulated • ETIOLOGY: Granuloma inguinale • MORPHOLOGY: safety pin appearance • Intracellular inclusions in macrophages Donovan bodies • SYMPTOMS: painless, expanding, suppurative ulcers • ”Beefy-red” tend to bleed easily Human Papilloma Virus (HPV) • PATHOGENESIS OF WART: • • • • • • Infection of basal layer, cell growth stimulation by early genes Prickle cells in stratum spinosum increases Differentiation of basal cells results in transcription of viral genes Skin becomes thicker (hyperkeratosis) Epithelial spikes (papillomatosis) Late gene expressed • SYMPTOMS: • • • • Non-genital skin warts Non-melanoma skin cancers: Basal Cell carcinoma, Squamous Cell carcinoma Benign laryngeal tumor Condylomata accuminata: external warts on perineum, anus, penis (HPV11) • VIRULENCE: • E6 + E7: bind p53 and Rb (high-risk strains HPV16/18) • Types 16 + 18 + 31 + 33= Cervical cancer • Types 6 + 11= Condyloma acuminatum (NOT LATA!! That is syphilis!) • Vaccines= Bivalent, Quadrivalent(Gardasil), Enneavalent (Gardasil-9) Thanks for watching! Don’t forget to subscribe!
