Teja_Etilogy

8/8/2019 Teja_Etilogy

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ETIOLOGY CLINICAL AND LAB DIAGNOSIS

Candidiasis: The genus candida encompasses more than 150 species ubiquitous in

nature these organisms are found on inanimate objects in foods and on animals and are

normal commensals of human. Candida is a small this walled, ovoid yeast that measures

4-6 mm in diameter and reproduces by budding organisms occur in three.

The human pathogens are C albicans, C guithermondii, C Krusei, C glabrate and fewother. They vitamin the gastrointestinal tract, the female genital tract and the skin.

Etiologic Agent: Candida is a small this walled, ovoid yeast that measures 4-6 mm in

diameter and reproduces by budding. The organism of this genus occurs in three forms

in lessue as blastospores, psendo hyphen and hyphen.

Pathogenesis: In the most serious form of Candida infection the organisms disseniate

homogenously and form micro abscesses in organs

Innate immunity is the most important defense mechanism against disseminated

Candidiass.

Main clirical manifectations are mucoentaneous candidiasis and deeply invasive

candidiases.

Mccourtaveous: The chemical manifestations are mostly thrust and vulvo vagina

candidacies. The influence of reproductive harmones in adolescents cause vast changes

in the tissues and increase susceptibility of infection.

Vulvovaginal candiasis: Vulvovaginal candidiasis produces valuar pruritis, burning and

irrilation sings of candidiasis include valvar erythema, edema, fissures and tenderness.

A white scanty, vaginal discharge in the form of white plagnes or cotton cherse like

curds adherent loosely to vaginal mucosa. C albicans accounts for nearly all cases of

vaginal candidiasis. Volvovaginal candidiasis occure in women with mentrolled diabetes,

pregnancy debilitation and immune suppression.

Diagnostic Criteria: Chemical and laboratory based on chemical fudings, scanty

discharge with thick cheesy or curdy precipitate adherent to the vagina and labia

associated with intense purities. May be accompanied by excoriation and inflammation of

valve and vagina.

Lab diagnosis: The diagnosis of vulvovaginal candidiasis on is by demonstration of

psendo hyphae or hyphae by microscopic examination of vaginal fuid.

To a drop of the suspension of vaginal discharge in saline on a slide, add or drop of 10%

KOH sohetion and examinine under microscope.

Gram stained smeas of vaginal discharge shous oval budding yeast calls.


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Culture on saborauds metimom reveals rounded oroval shaped colomies 1-2mm in

diameter within 48-72

Trichomoniasis

Microbiology: Various species of trichomonads can be found in month and

gastrointestinal tract trichomenos vaginalis one of the most prevalent protozoal

parasites is a pathogen of the genitor irrirary tract and a major cause of symptomatic.

Vaginitis: Trichomonas vaginelis is a pear shaped, actively motile organism that

measures about 10x7mm inhabits the lower genital track of females and the urethreat

and prostate of males.

Clinical features of vaginal trichomoniasis vaginal trichoniasis characteristically produces

a profuse, yellow, purulent, homogenous vginal discharge with varlvar and valval

epithehium and pefechical lesions on the cessi and The so called straw berry cesvix.

Laboratory findings:

Wel preparation technique: The swab is agitated in 0.9% saline and a drop of this is

observed under wet mount microscopy. Motile pear shaped organism is seen in positive

specimens. Culture is the gold standard technique with a sensitivity of more than 70%

but takes upto 7days for results to be obtained.

Polymerase chain reaction and vatex agghtinetion.

Bacterial Vaginosis

Bactirial vaginosis is caused by G. Vaginals, Mycoplasma honious and several anaerobicbacteria mobiluncs prevolulla species and pepto streptococcus spp

Hacurophils vaginalis or gardnerella naginalis is the most associated organism.

Chiwcalfealurss: Bacterial vaginosis is connentionally diagnosed clinically with

1. Increased white homogenous molodorous vaginal discharge.

2. Vaginal discharge with a PH of 4.5

3. Liberation of a distinct fishy odor attributable to volalite amines.

4. Microscopic demonstration of clue cells coated with coccobacillary organisms which

have a grannler appearance and indistinct boarders.

Laboratory findings:

Grams stained smear of vaginal discharge shows clue cells with bacilli, gram negative

roads of gram which are gardeneralla vaginalts and plcomorphic bacterias which include

other anaerobic bacteria.


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Mucopurulent cervicits refers to inflammation of the columnas epithelwon and

subepithlivrn of the endocervix and contigons columner epithetium that exposed an

epithetium position on the exocercix.

Mucopurulent cerlicts is caused by Nisseria gonorrhoeae and Chlamydia trachomatis

Pelvic inflammatory disease

The terms pelvic inflammatory disease usually refers to infection that ascends from revix

or vagine to involve the endometrial and/ or fallopian tubes. Infection can extend

beyond the reproduction treet to cause peritonitis, perihepathis, pewsplenitis or pelvic

abscess.

The agents most after implicated in PID include the primary causes of endocercities

Nisseria gnorrhoeae and Chlamydia trachmetis.

Gonococcal infections

Gonorrhea is a sexually transmitted infection of epithelium and eomononly maniferts ascericitis, urethritis, proctitis and conjunctivitis. If untreated lead to complications such as

endometritis, salpingitis, tuboovariam abscess, bartholivitis and peritonitis in female

patients. Gonorrhoea is transmitted from males to females more efficient by than in

opposite direction.

Etiologic agent

Neisseria gonorrhea is a gram negative non motile, non- spore forming organism that

grows singly and in pairs. Neisseria gonorrhoeae other species by their ability grow on

selective medva.

Clinical manifestations: Gonococcal infection in females in the most common STI in

women women infected may remain asymptomatic or develop symptoms which include

Scant vaginal discharge and deserve and dysparwnea.

Physical examination way reveal a prulent discharge (Mucopus) from the cervical os

Laboratory diagnosis: Grams stain of vaginal discharge Gram negative infracelluler

monococci and diplococcic

Polymorphonuclear leucocylee (Poly morphe Nucholytes) (PMNS) are often seen an the

endocervix on grams stain vaginal discharge should be inocluted on to a plate of Thayer

martin medium for culture.

Nucleic acid pro be tests are sometimes substituted for culture for alirect defection of N.

Gonorrhoeae in urogential specimens.


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Chlamydia infections

Three Chlamydial species cause human infections Chlamydia trachomatis, Chlamydia

and Chlamydophite pneumonia

Chlamydia are obhigate intracellular bacteria that are classified in order Chlamydiales

Chlamydia possess both DNA and RNA, have a cell wall and ribosomes similar to those of

gram negative bacteria.

Etiological Agent

Unique feature of all Chlamydia is their complex reproductive cycle. Two forms of

microorganism the extra cellular elementary body (EB) and the intracellular reticulate

body (RB). EBs attach to susceptible target cells and enter the cells inside a

phagosome and reorganize into RBS which are adapted to intracellular survival and

multiplication.

Pathogenesis: Chlamydia trachomatis preferentially infects the columnar epithelium ofthe eye and the respiratory and genital tracts.

Clinical manifestations: Non gonococcal uretheitis in men and muccopurulent cervicitis in

women. C. trachometis is identified in fallopian tubes of 50% of women with pelvic

inflammatory disease. Mucopurulent cercicitis is followed by endowmetritis,

endosalphingitis and pelvic peritintis.

Lymphogramuloma venerum is caused by Chlamydia trachomatis strains of the L1, L2

and L3 serovars.

Laboratory diagnosis

Four types of laboratory procedures are available to confirm C trachomatis infection 1.

Direct microscopic examination of issue scrapings for typical intracy to plasmic inclusions

or EBs.

Isolation of organism in cell cultures Direct immune fluorescent antibody slide test by

straining with fluorescein conjected monoclonate antibody for Chlamydial antigens

Observation of fluorescing EBs confirms the diagnosis.

ELISA techniques are available for detection of Chlamydial antigens.

NAAT can defect Chlamydia genes in forst void urine samples and vaginal discharge

swabs.

(ELISA Enzyme linked immune sorbent assay)

(NAAJ Nucleic acid amplification test)


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Syphilis

Syphilis, a chronic systemic infection caused by treponema pollidum subspecils pallidum

is usually sexually transmitted.

The spirochaetales include three genera that are pathogenic for humans.

Leptospira which causes human leptospirosis Borrelia which causes Lyme disease.

Genus Treponeura includes T pathidum subspecies pallidum eaures veneral syphilis,

T.pathidum subspecies pertenue which causes yews subspecies endemicum which

causes endomic syphilis or beject and T. carateum which causes.

Actiologic Agent

T. pallidurn subspecies pallidum is a thinspirale organism, has a cell body surrounded by

a trilaminea cytoplasmic membrane, a delicate peptidogycan layer and a lipid rich onter

membrane-

Pathogenesis: T pathiduon penetrates infect mucons membranes or micro babrasions in

skin and mucons membrances and enters the lymphaties and blood to produce systemic

infection and snetastaicfoci.

Clinical manifestations:

Primary syphilis: Primary chancre is a single painless papule that rapidly crodes and

becomes indurated with a characteristic cartilaginous consistency a palpation of the edge

and base of the ulcer. Common sites of occurrence are cerix and labia in women.

Secondary Syphilis: The protean manifestations of secondary syphilis are localized ordiffuse mucoculaneou lesions and generalized non tender lymphadenopathy.

Typical skin rash consisting of macular, popular, papulo squmous and pustalar lesions

muconspatches. Papules enlarge to produces condylomata late.

Typical mucons pateh is a painless siluverygrey erosion evith a red periphery. Latent

syphilis Positive serologic tests for syphilis and absence of clinical manifestations.

Laboratory examination:

Dark field microscopy and immunoflooure antibody and training are done to identify

spirochete in most lesions.

Serologic tests for syphilis:

a) Non treponemal tests RPR and VDRL tests measure JgG and JgM directed against a

cardiolip lecithic cholesterol antigen complex.

b) Trepomal Tests: Flourscent treponemal antibody absorbed (FTA ABS) test.


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Micro heamagglutination assay to T. pathidurn.

Uses of serologic tests

1. Screening or diagnostic pruposis (-RPR-VDRL)

2. Quantitative measurement of antibody to assess clinical syphilis activity and monitor

response to therapy.

3. Confirmation of a syphilis diagnose in patients reactive to RPR and VDRL

Herpes simplex viruses

Herpes simplex viruses (HSV-1 HSV-2) produce a variety of infections involving

mucoculaneons surfaces, central nervons system and on occarion visceral organs.

Etiologic Agent

The genome of Herpes Simplex Virus is a linear double strand DNA molecule that

encodes more than 90 transcription units.

The viral genome is packaged is a regular icosahedra protein shall composed of 162

copsomeres. The onter covering of the virus is a lipid containing member are acquired as

DNA containing eapsid buds through the inner nuclear membrane of the bost cell

Pathogenesis: Exposure to HSV at nucosal surfaces or abrabled skin sites permits entey

of virus and initiation of its replication in cells of epidermis and dermis.

Genital infections: First episode of primary genital herpes is characterized by fever,

headache, malvse and majalgins pain, itching dysuria vaginal discharge and tewderinguinal lymphodenopethy are the predominant local symptoms widely speaced bilateral

lessons of external genelaua are characteristic.

Diagnosis

Clinical diagnosis: Presence of characteristic multiple vesicular lesions on an

erythemators base.

Lab diagnosis: Staining of scrapings from the base of lesions with weights, Giemsas

Tzank preparation, or paparicolovns stain to defect gaint cells or intranceclear inchisions

of herpes virus infection.

HSV DNA detection by PCR is the most sensitive laboratory technique.

Human papillma virus infections

Human papillma viruses selectively infect the epithlim of skin and mucous membranss.

These infections may be symptomatic, produce warts and are associated with a variety

of being and mehignant neoplarms.


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Etiologic Agent papilloma viruses are members of the family pabillomaviride. They are

non evveloped, measure 50.55mm in diameter, have icosahedral capsids compsed of

72 capsoneres and contain a double. Strand circular DNA genome of 7900 base pairs.

HPV-1 causes planter waters

HPV-6 causes anogental warts and GPV = 16 infection can produce cervical dysplasia

and inverine cervical cancer.

Pathogenesis: The incubation period of HPV disease is usually 3-4 months and may

range from 1 month ot 2 years. All types of squamous epithelium can be infected by

HPV.

Episomal HPV DNA is present in the nuclei of infected cells in benign lessons caused

HPV. HPV infection also elicits a detectable serologic response in many patients.

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