Normal Flora Of Urinary And Genital Systems PDF

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normal flora urinary tract infections urogenital system medical microbiology

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This document covers the normal flora of the urinary and genital systems, outlining the components, their importance, and the different strains found in each part of the system. It also includes a simple test focusing on the most prevalent microorganism in the vagina that is also protective.

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CHAPTER (1) NORMAL FLORA OF URINARY AND GENITAL SYSTEMS ILOs By the end of the chapter the student will be able to: - Identify the component of urinary and genital systems. - List the importance of n...

CHAPTER (1) NORMAL FLORA OF URINARY AND GENITAL SYSTEMS ILOs By the end of the chapter the student will be able to: - Identify the component of urinary and genital systems. - List the importance of normal flora. - Identify the different groups of strains in each site 75 Normal flora of urogenital system The bladder and upper urinary tract are normally sterile. The urethra and the perineum contain a few commensals (bacterial flora) which may contaminate urine when collected. With female patients, the urine may become contaminated with organisms from the vagina. As the vagina is located close to the anus, can be colonized by members of the fecal flora. Vaginal contamination: indicated by the presence of epithelial cells (moderate to many) and a mixed bacterial flora. 76 Commensals include: 1- Coagulase negative Staphylococci (excluding S. saprophyticus) in approximately 5% of women, which predisposes them to toxic shock syndrome. 2- S.viridans & non-haemolytic Streptococci, which is an important cause of sepsis and meningitis in the newborn and is acquired during passage through the birth canal. 3- Lactobacilli 4- Diphtheroids 5-Anaerobic cocci 6-Anaerobic gram-negative bacilli 7- Commensal Mycobacteria 8- Commensal Mycoplasma N.B: Most urine specimens will contain fewer than 104 contaminating organisms per ml. LACTOBACILLI: It is a normal flora of vagina, It has a beneficial effect due to acid production which inhibits colonization with pathogenic organisms, since their suppression by antibiotics can lead to overgrowth by C. albicans resulting in vaginitis. Estrogens (sex hormones) promote the growth of Lactobacilli by enhancing the production of glycogen by vaginal epithelial cells. The glycogen quickly breaks down into glucose, which the lactobacilli metabolize into lactic acid. Before puberty and after menopause, when estrogen levels are low, Lactobacilli are rare and the vaginal pH is high, so often associated with higher rates of urinary tract infections 77 Test yourself 1- Which of the following is the most prevalent microorganism in the vagina that may also be protective? a. α-hemolytic streptococci b. Lactobacillus c. S. epidermidis d. E. coli e. B. fragilis 78 CHAPTER (2) URINARY TRACT INFECTION (UTI) ILOs By the end of the chapter the student will be able to: 1) Understand about the different types of UTI presentations. 2) Recognize the uropathogenic microorganisms, and their pathogenesis, laboratory diagnosis and treatment as well as their methods of prevention. 3) Describe & interpret various diagnostic lab methods 4) Enumerate complications associated 79 Urinary tract infections (UTI) A urinary tract infection occurs when bacteria and white blood cells are present in the urine of a patient with symptoms of infection of the urethra, urinary bladder, or the kidney. Classification of UTIs: 1- Upper UTIs: Pyelonephritis: Infection of the kidney, manifested by loin pain, pyuria, rigors, fever, often bacteraemia. 2- Lower UTIs: Urethritis: infection of the urethral tract manifested by dysuria, urgency and frequency of urination. Cystitis: Infection of the bladder, manifested by frequency, dysuria (pain on passing urine), suprapubic pain, sometimes haematuria and usually pyuria (increased number of pus cells in urine). Prostatitis: Prostatitis is inflammation of the prostate, which can be due to infection or other causes. Important Definitions: Bacteriuria: The presence of bacteria in urine, Significant: 105 organisms or more per ml in pure culture Sterile pyuria: The presence of pus in urine (more than 10/HPF), while no growth on ordinary culture media is detected. Its causes are: 1- Female genital tract infections. Because of the shorter urethra and the close proximity of the urethra to the anus. Also, sexual intercourse promotes contamination of the urethral opening with fecal organisms and contributes to the increased number of infections in women 2- Renal tuberculosis, 80 3- Non -gonococcal urethritis as C. trachomatis infection and leptospirosis 4- When a patient with UTI has been treated with antimicrobials. 5- Prostatitis 6- Tumors 7- Infections with anaerobes. Causes of UTI Bacterial Gram negative enteric bacteria 1-E. coli: 80% of causes of UTI; either community or hospital acquired infections. 20% of UTI caused by: 2-Klebsiella spp. (Revise Page 41 Respiratory system) 3-Proteus spp. 4- Pseudomonas aeruginosa 5-Enterobacter 6- Serratiae Gram positive cocci 1-Staphylococcus saprophyticus in sexually active females between theages of 13 and 40. 2- Enterococci 3-Streptococci Virus Adenovirus Adenovirus infection may cause acute hemorrhagic cystitis in children Fungal Candida spp Histoplasma capsulatum 81 Mode of transmission: 1- Ascending of the organisms up the urethra to the bladder is the most common means of acquiring a urinary tract infection. 2- Blood-borne infections of the urinary tract can occur but are infrequent and usually lead to renal abscess. Clinical manifestation: 1-Pain and discomfort during urination (dysuria). 2- Urgency and frequency of urination, 3- Suprapubic tenderness 4- Fever, flank pain and tenderness in case of pyleonephritis Laboratory Diagnosis: 1- Urine analysis should be performed in patients symptomatic for urethritis and cystitis without kidney involvement to determine 2- Quantitative culture to determine the causative organisms. Details discussed in practical part. 82 Some important bacterial causes of UTI 1- Escherichia coli Most predominant facultative anaerobe in GIT Indicator of fecal pollution of water Morphology: one of enterobactericae, Gram -ve bacilli, Motile, may be capsulated. Culture Characteristics: Rose pink, lactose-fermenting colonies on MacConkey’s agar. Virulence factors: 1- Fimbria: that allows adhesion to epithelium of urinary tract. 2-Capsular antigens: that interferes with phagocytosis 3- Haemolysin : toxin that responsible for kidney damage Laboratory Diagnosis: Sample: Urine Diagnosis: Ø Direct Detection: Gram stain: Gram-negative bacilli. Ø Culture: MacConkey & Blood agar, 24hrs, 37°C. Quantitative urine culture. Ø Identification: colonies examined for morphology, gram stain and oxidase (gram negative, oxidase negative considered Enterobactericae) On MacConkey’s agar. E. coli, forms pink colonies. Biochemically: (see practical part) Treatment: according to antibiotic sensitivity test. 83 2- Proteus Morphology One of enterobactericae, Gram- negative bacilli. Culture Characteristics: pale Lactose non-fermenter colonies on MacConkey’s agar. Swarmming on Nutrint agar. Biochemical Reactions: Urease test: +ve N.B: salmonella → Urease -ve (DD from proteus) 3- Staphylococcus saprophyticus Ø Gram-positive cocci in clusters. Coagulase-negative. Ø Resistant to novobiocin in contrast to S. epidermidis, which is sensitive. Ø Causes community-acquired urinary tract infections in young women (but Escherichia coli is a much more common cause). 84 4- Enterococcus Characters of the genus Enterococci are similar to Streptococci in being: Gram-positive cocci arranged in pairs or short chains. Enterococci 1. Catalase negative. 2. Most strains react with Lancefield group D antiserum. 3. Facultative anaerobes. 4. Usually non-hemolytic or alpha hemolytic, occasionally beta-hemolytic 5. Enterococci differ from streptococci in being able to: Grow at 45°C. - Grow in broth containing 6.5% NaCl (salt tolerant). Tolerate bile salts (in bowel and gall bladder). Hydrolyze esculin (a polysaccharide) producing black colonies on esculin- containing media. 85 5- Mycoplasma Smallest free-living microorganisms, lack cell wall. Highly pleomorphic – no fixed shape or size – as they lack cell wall. No cell wall means also they are resistant to penicillins, cephalosporins and vancomycin, etc. Require complex media for growth, including sterols Major antigenic determinants are glycolipids and proteins, some cross react with human tissues. Established pathogens: M. pneumoniae Presumed pathogens: M. hominis, Ureaplasma urealyticum Non pathogenic: M. orale, M. buccale, M. genitalium, M. fermentans Saprophytic – present mainly on skin & in mouth. Pathogenicity: Produce surface infections – adhere to the mucosa of respiratory, gastrointestinal & genitourinary tracts with the help of adhesins. 86 Diseases Caused by Mycoplasma Organism Disease M. pneumoniae Upper respiratory tract disease, tracheobronchitis, atypical pneumonia, (chronic asthma). M. hominis Pyelonephritis, pelvic inflammatory disease, postpartum fever. M. genitalium Nongonococcal urethritis. U. urealyticum Nongonococcal urethritis, pneumonia and chronic lung disease in premature infants. Ureaplasma urealyticum: Strains of mycoplasma isolated from the urogenital tract of human beings & animals. Form very tiny colonies - hence called T strain or T form of mycoplasmas. Hydrolyzes urea Cause genital infections, that transmitted by sexual contact ¬ Men: Nonspecific urethritis, proctitis & Reiter’s syndrome ¬ Women: acute vaginitis, cervicitis, salpingitis, PID ¬ Complication may occur as a result of these infections as infertility, abortion, postpartum fever, chorioamnionitis & low birth weight infants Treatment ¬ Tetracycline or erythromycin ¬ U. urealyticum is resistant to tetracycline ¬ M. hominis is resistant to erythromycin and sometimes to tetracyclin, Clindamycin for these resistant strains Prevention: Abstinence or barrier protection, No vaccine 87 6- Leptospira: Morphology: it is one of member of spirochetes. Leptospira is fine spiral has hooked ends, about 0.1 μm in diameter, shown by a dark-field microscope. L. interrogans stains poorly and is difficult to see under a normal light microscope. Culture Characteristics: it is an obligate aerobe that can be grown in a variety of artificial media supplemented with rabbit serum. Clinically: cause leptospirosis (Weill’s disease), which is primarily a disease of domestic or wild animals, but it can be passed to humans and sometimes causes severe kidney or liver disease. Mode of transmission: one of zoonotic disease. Animals infected with the spirochete shed the bacteria in their urine for extended periods. Humans become infected by contact with urine-contaminated water; pathogen enters through minor abrasions in the skin or mucous membranes of the upper digestive system. Pathogenesis: It ranges from mild self limiting febrile illness to Fulminant fatal illness (hepatorenal failure). After an incubation period of 1 to 2 weeks, headaches, muscular aches, chills, and fever abruptly appear. 88 Several days later, the acute symptoms disappear, and the temperature returns to normal. A few days later, however, a second episode of fever may occur. Leptospires are observed within non phagocytic cells of infected patients. The kidneys and liver become seriously infected (Weil’s disease); kidney failure is the most common cause of death. Also can affect the lungs with massive bleeding Laboratory diagnosis: A. Specimen: blood if in the first week, if in second week urine and CSF. B. Direct detection: by dark field microscopy or PCR for detection of DNA in specimen. C.Cultivation: Fletcher's or Staurt's medium colonies appear within 1-2 weeks D. identification: microscopic agglutination test or PCR. E. Serology: detection of specific IgM by ELIZA highly sensitive. Treatment: Doxycyline (a tetracycline) is the recommended antibiotic for treatment; however, administration of antibiotics in later stages is often unsatisfactory. 89 PROSTATITIS Definition: Prostatitis is inflammation of the prostate, which can be due to infection or other causes. It is important in the differential diagnosis of UTI, as patients with acute prostatitis present with the same symptoms of UTI. Causes: 1 Neisseria gonorrhoeae 2- Chlamydia trachomatis 3- Mycoplasma and Ureaplasma 4- E. coli 5- S. aureus Clinically: Clinical manifestations may present with acute onset of fever, dysuria, urinary frequency, and severe pain with palpation of the prostate. Patients may be very ill and can present with severe sepsis. In contrast, chronic prostatitis presents with more subacute onset of dysuria, frequency, urinary hesitancy, and pelvic discomfort. 90 Diagnosis: The diagnosis of acute bacterial prostatitis is often confirmed by the finding of an acutely tender prostate on digital rectal exam. Expressed prostatic secretion or urine may be collected after massage of the prostate via rectum. Treatment: Antimicrobial therapy with excellent penetration to the prostatic tissues is recommended for treatment of prostatitis. Fluoroquinolones and trimethoprim- sulfamethoxazole both achieve high levels in the prostate. Antibiotic susceptibility testing should be used to guide treatment of infecting pathogens. Prevention: Prompt treatment of acute prostatitis may reduce the risk of development of chronic prostatitis. 91 Test yourself 1-One of the following organisms is the most important cause of urinary tract infections: a) HIV b) Escherichia coli c) S.typhi d) Bacteroides fragilis e) H.influenza 2-One of the followings is true about mycoplasma: a) Symmetrical in shape b) Susceptible to beta-lactam antibiotics c) Contain sterol in cell wall d) M. hominis cause gastroenteritis e) Can be stained with Gram stain 3-Enterococcus faecalis is: a) A frequent cause of pyogenic infections b) A Gram-negative coccus c) Strict aerobe d) Catalase negative e) Associated with infection in hip prostheses 4- Ureaplasma urealyticum a) Form very tiny colonies - hence called S form of mycoplasmas. b) Hydrolyzes ammonia c) Transmitted by droplet d) In men cause nonspecific urethritis, proctitis. e) Vaccine can be taken for its prevention 92 CHAPTER (3) SEXUALLY TRANSMITTED DISEASES (STDs) & GENITAL INFECTIONS ILOs By the end of the chapter the student will be able to: 1) Understand about the different causes of STDs. 2) Recognize their pathogenesis, laboratory diagnosis and treatment as well as their methods of prevention. 4) Describe & interpret various diagnostic lab methods 5) Enumerate complications associated with genital infections 6) Define bacterial vaginosis causes, pathogenesis, diagnosis and treatment 93 Sexually transmitted diseases (STDs) These are infections that pass from one person to another by sexual contact (by contact, through vaginal secretions and semen); their clinical presentation may include the following: 1- Urethritis and cervicitis (gonorrhea, chlamydial infections, and nongonococcal urethritis), 2- Genital ulcers (genital herpes, syphilis, and chancroid). 3- Warts (human papillomavirus infection; HPV) Causes of STD Bacterial 1- Neisseria gonorrhoeae etiology 2-Treponem pallidum 3- Haemophilus ducreyii 4- Chlamydia trachomatis serotypes L1, 2, 3 and D-K 5-U.urealyticum Viral 1-HSVs (Herpes simplex virus) etiology 2-HPV (Human papillomavirus) 3-HIV 4-HBV (Hepatitis B virus) 5-CMV (Cytomegalovirus) 94 1- DISEASE CHARACTERIZED BY URETHRITIS OR CERVICITIS Urethritis is an infection characterized by urethral discharge of mucopurulent or purulent material and by dysuria or urethral pruritus. The most common causes of urethritis & cervicitis are: 1- Gonococcal urethritis (Neisseria gonorrhoeae, the most common cause) 2- Non- Gonococcal urethritis due to: Ø Chlamydia trachomatis serotypes D-K, Ø Ureaplasma Urealyticum Ø Mycoplasma hominis Ø Trichomonas Vaginalis. 3-Others as E.coli, Staphylococci, Streptococci, HPV, HSV, adenovirus 95 1- Gonococcal urethritis: Neisseria gonorrhoeae (GONORRHOEAE) Morphology: Neisseria gonorrhoeae is a small gram-negative diplococci that have flattened surfaces between the adjacent individual cocci (shaped similar to a kidney or a coffee bean). Culture media: Modified Thayer-Martin medium (chocolate agar containing vancomycin, colistin, and nystatin) must be used to grow N. gonorrhoeae from clinical samples. N. gonorrhoeae will not grow on blood plates. Neisseria gonorrhoeae in culture Pathogenesis & clinical presentation: Men: Gonococcal infection in heterosexual men usually involves only the urethra. Patients present with inflammation and erythema around the opening of the urethra, a profuse purulent urethral discharge, and dysuria. § Some men with gonorrhea are asymptomatic and are more likely to develop complications that include: Ø Inguinal lymphadenitis, Ø Urethral stricture, Ø Epididymitis, prostatitis, Ø Septic arthritis, Ø Disseminated gonococcemia with skin lesions Ø Infection in homosexual men involves the urethra, the anal canal, and sometimes the pharynx. Ø Anorectal infection is manifested by rectal pain and mucopurulent rectal discharge. 96 Women: with gonorrhea are asymptomatic approximately one third of the times and do not seek medical treatment. The usual site of infection is the cervix sparing the vagina, manifested upon examination by a purulent vaginal discharge or an inflamed and purulent cervix. Infection of the cervix frequently results in contiguous spread along mucous membranes to the urethra and rectum resulting in anorectal infection manifested by pain, purulent discharges, and rectal bleeding. About 10–20% of cervical infections result in pelvic inflammatory disease (PID) due to upward spread of the bacteria resulting in endometritis, salpingitis, tubo-ovarian abscesses, and pelvic peritonitis. Disseminated gonococcal infections occur in about 1–3% cases of gonorrhea. Most patients are initially asymptomatic. Manifestations include low-grade fever, migratory polyarthralgia, septic arthritis with increased pain and swelling of the joints, purulent synovial fluids, and tenosynovitis, and petechial skin lesions. Neonatal infections: from infected mother to neonates, in the form of, conjunctivitis and pharyngitis. Conjunctival infections (e.g., ophthalmia neonatorum) can rapidly cause blindness. Sepsis, arthritis, and meningitis may occur. Ophthalmia neonatorum 97 Virulence factors: q Pilli and outer membrane protein (mediate attachement) q Outer membrane porins (antiphagocytic) q Lipo-oligosaccharides (LOS) endotoxin q IgA1 protease ( adherence and colonization) DIAGNOSIS: Specimen: Urethral /Cervical Discharge Direct Detection: 1. Gram-stained smear: Intracellular gram-negative diplococci in some neutrophils (Diagnostic in acute male gonorrhoea). A Gram stain of urethral discharge due to Neisseria gonorrhoeae. Notice the large number of polymorphonuclear leukocytes and the intracellular gram-negative diplococci in some cells (arrows). 2. Ag detection by ELISA 3. Nucleic acid detection by Nucleic acid probe Cultivation On Modified Thayer-Martin medium. 98 vIdentification at the genus level: Gram –ve diplococci and oxidase +ve vIdentification at the species level: Sugar utilization , by antigen detection or nucleic acid detection by amplification and probe detection. TREATMENT AND PREVENTION Ø Because many strains of N. gonorrhoeae are resistant to penicillin (e.g., penicillinase- producing N. gonorrhoeae), cephalosporins and quinolone antibiotics are now commonly used to treat these infections. The drugs of choice for uncomplicated cases of cervicitis, pharyngitis, urethritis, and proctitis are ceftriaxone or ciprofloxacin. Ø Disseminated infections require a parenteral antibiotic treatment with ceftriaxone until 24–48 hours after improvement begins. Then oral treatment with ciprofloxacin should be given for at least 1 week. Ø Ophthalmia neonatorum can be treated with ceftriaxone. Routine treatment with silver nitrate (AgNO4), erythromycin, or tetracycline applied directly to the eye following birth prevents ophthalmia neonatorum. Ø Preventing transmission requires improved education of sexually active individuals, proper reporting, follow-up of patients and their contacts, use of condoms, and chemoprophylaxis to prevent ophthalmia neonatorum. Culturing pregnant women for gonorrheal infection before delivery and treating those who are infected can prevent gonorrheal infections of the newborn. 99 B. SYPHILIS Causative organism: Treponema pallidum, which are thin delicate spiral-shaped rods with characteristic corkscrew motility and seen only via dark-field microscopy. T. pallidum Clinically: The manifestations of syphilis depend on the stage of disease the patient is experiencing. There are four stages of syphilis in adults: primary, secondary, latent, and tertiary syphilis. 1- Manifestations of primary syphilis include a highly infectious hard painless ulcer called chancre and regional lymphadenitis. The hard chancre develops after an incubation period of approximately 3 weeks and will usually heal within 3–6 weeks. Regional lymphadenopathy; swollen, painless and firm, non-suppurative lymph nodes will develop. 2-The manifestations of secondary syphilis usually begin 6–8 weeks after the appearance of the initial chancre and may overlap the time when the primary chancre is present. There are four cardinal features, which are: 105 1-Generalized skin rash which are usually macular, but can be papular or nodular. These lesions are also found on the palms and soles 2- Generalized lymphadenopathy with Systemic manifestations, which include malaise, anorexia, headache, sore throat, arthralgia, low-grade fever. 3- Condyloma lata, which are moist flat, raised lesions usually seen around the anus or genitals. 4- Mucous patches in the mouth and on the tongue It lasts 3–6 months, and the patient then enters the latent phase. 3-Latent syphilis is by definition the stage in which the results of a serologic test are positive for syphilis in the absence of any clinical symptoms. The duration of the infection is highly variable. Approximately one fourth of patients experience a relapse of secondary syphilis during this latent period, and only about one third of patients who progress to latent syphilis have signs and symptoms of tertiary syphilis. 4-Tertiary, or late, syphilis is a noncontagious but highly destructive phase of syphilis that develops over many years. Tertiary syphilis presents in three basic forms: 1-Gummatous syphilis (granulomatous lesions that coalesce in the skin, bone, and mucous membranes), 2-Cardiovascular syphilis, 3- Neurosyphilis. DIAGNOSIS Diagnosis of syphilis involves evaluation of presenting signs and symptoms. A. Direct detection: An examination of exudative material in syphilitic lesions using a dark field microscope or a fluorescence microscope using fluorescein labeled anti- T.pallidum antibodies will confirm diagnosis of a patient in early primary syphilis before serologic test results are positive. B. Serologic tests are frequently used and are positive within 1 week after the appearance of the chancre in primary syphilis. The two different types of serologic tests used are the treponemal and the nontreponemal tests. 106 Non-treponemal tests: 1- Used for screening and to determine treatment efficacy. 2-It measures non specific antibodies that develop to cardiolipin lecithin following damage of host cells by T. pallidum. 3-Disadvantages: False positive may occur due to cross reacting antibodies that produced in several other conditions, including viral hepatitis, infectious mononucleosis, malaria, pregnancy, and patients with connective tissue disease. 4- Advantages: These tests are inexpensive, rapid and simple to perform. So used for screening. They are also used for follow up of treatment, since reactivity declines or disappears within 6-18 months of effective therapy. 5-They include the following flocculation tests: - The venereal disease research laboratory (VDRL): highly valued. The flocculation is seen by M/E. - The rapid plasma reagin (RPR) card test: This test can be applied on plasma as well as serum & CSF. The flocculation is seen with the naked eye RPR test +ve (Right)…. _ve (Left). Treponemal tests 1- Used to confirm a positive non-treponemal test. 2- These tests detect specific antibodies. The T. pallidum antigen is used. 3- Disadvantage: They are not screening tests because they are expensive & difficult to perform. 4- Advantage: These tests detect specific antibodies for cellular components of the organism, because they are specific, they are used in confirming or ruling out reactive non-treponemal test result. They remain reactive for life. 107 5- They include: § The fluorescent treponemal antibody absorption (FTA-ABS) test. § T. pallidum haemagglutination assay (TPHA). § T. pallidum immobilization (TPI) test. § The EIA & the Western blot. A. Non treponemal test B. Treponemal test Non specific. Used for screening and to Specific tests. Used to confirm a positive non- determine treatment efficacy treponemal test. It measures antibodies that develop to Detect specific antibodies for cellular cardiolipin lecithin following damage of host components of the organism, cells by T. pallidum Antigen: Cardiolipin Specifc T. pallidum antigen is used Advantages: These tests are inexpensive, rapid Advantage: These tests detect antibodies and simple to perform. So used for screening. specific for cellular components of the organism, Disadvantages: False positive may occur due Disadvantage: They are not screening tests to cross reacting antibodies that produced in because they are expensive & difficult to other conditions perform Treatment Penicillin is the drug of choice for treatment of syphilis 108 C. CHANROID Chancroid or soft chancre is a rare disease. Causative organism: Chancroid is an acute sexually transmitted infection that is caused by the gram-negative coccobacillus Haemophilus ducreyi, which is similar to H. influenzae in that neither can grow on blood agar but can only grow on chocolate agar plates or on plates supplemented with hemin and nicotinamide adenine dinucleotide (NAD); as it requires factors X (hemin) and V (NAD) for growth. Clinically: There is an incubation period of 1–14 days after exposure to H. ducreyi. The soft chancre begins as a small inflammatory papule and eventually develops into a chancre. In contrast to the chancre seen in primary syphilis, chancroid are painful and lack induration. It is accompanied by an acute, painful inflammatory inguinal lymphadenopathy that develops in over half of patients. DIAGNOSIS Usually clinical because it is highly fastidious; difficult to be grown in the lab Ø Specimen: scrapings of the ulcer base Ø Direct microscopy: small Gram -ve rods in strands in lesions, usually associated with other pyogenic microorganisms Gram Stain of H. ducreyi Culture & identification: requires X factor but not V factor, grown best on chocolate agar containing vancomycin and 10% CO2 at 33°C. 109 Treatment: Chancroid can be treated with azithromycin, ceftriaxone, ciprofloxacin, or erythromycin. If treatment is successful, chancres usually improve within 7 days after therapy. Clinical resolution of regional lymphadenopathy is slower than that of chancres and may require needle aspiration or incision and drainage. Comparison between different types of genital ulcers Number and Disease Location Tenderness Ulcer Appearance Adenopathy Herpes Clusters of Tender Uniform size clean Tender inguinal simplex ulcers on base erythematous nodes virus (HSV) labia and border penis Syphilis One or two Little to no Clean base Rubbery, mildly lesions on tenderness indurated border tender vagina and penis Chancroid One or two Painful Can be large, ragged, Very tender, lesions on and necrotic base, fluctuant labia and undermined edge inguinal penis; nodes may coalesce 110

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