Star Team

Picture 2: Blue Green Pigment on Ordinary Nutrient agar

www.google.com > Pseudomonas aeruginosa nutrient agar
http://www.bmb.leeds.ac.uk/mbiology/ug/ugteach/icu8/images/uti/pyocyanin.jpg

Enterococcus faecalis

Gram positive cocci in chains; Facultative anaerobe
Habitat is the human colon; urethra and female genital tract can be colonized
Hospital acquired UTI
Laboratory Diagnosis
Gram stained smear and culture
Alpha-, Beta-, or non-hemolytic colonies on blood agar
Catalase negative
Coagulase negative
Grows in 6.5% NaCl and hydrolyzes esculin in the presence of 40% bile
Serological test not useful
Treatment
Combination Therapy
Penicillin or vancomycin plus an aminoglycoide such as gentamicin

Proteus-Providencia-Morganella Family

Community and hosipital acquired
Gram negative rod; Facultative anaerobe
Presence in colon and vigorous motility contribute to their ability to invade the urinary tract
Laboratory Diagnosis
Highly motile and produce a swarming overgrowth on blood agar
Growth on blood agar containing phenylethyl alcohol inhibits swarming, thus allowing isolated colonies of Proteus and other organisms to be obtained.
Produce non-lactose fermenting colonies on MacConkey or EMB agar
Urease producing
TSI agar shows an alkaline slant and acid butt with H2S
Indole +
Treatment
Trimethoprim-sulfamethoxazole
Ampicillin
3rd generation cephalosporin

Enterobacter-Klebsiella-Serrtia Family

Gram negative rod with large polysaccharide capsule; Facultative anaerobe
Transmitted to the urinary tract by ascending spread of fecal flora
Endotoxin causes fever
Laboratory Diagnosis
Gram stained smear and culture
Characteristic mucoid colonies are a consequence of the organism’s abundant polysaccharide capsule
Lactose fermenting colonies on MacConkey’s agar
Voges Prooskauer +
Serratia marcescens: Red-pigmented colonies
Treatment
Cephalosporins alone or with aminoglycosides, but antibiotic sensitivity testing must be done

Picture 3: Serratia marcescens: Red-pigmented colonies

http://www.google.com/ > Serratia Marcescens agar
http://microvet.arizona.edu/Courses/JC-MIC205/S08/Images/pour_Serratia.jpg

Mycoplasma genitalium

Small, wall-less organism
Reproduce by budding, fragmentation or binary fission
Normal flora of the genitourinary tract
Laboratory Diagnosis
Serologic testing
Cold agglutinin titre of 1:128 or higher indicate recent infection
4 fold rise in antibody titre in complement fixation test
Treatment
Resolves spontaneously
Penicillins and cephalosporins are inactive due to lack of cell wall
Macrolide ( Erythromycin/ Tetracycline)

Ureaplasma urealyticum

Small, wall-less organism
Reproduce by budding, fragmentation or binary fission
Normal flora of the genitourinary tract
Laboratory Diagnosis
Serologic testing
Cold agglutinin titre of 1:128 or higher indicate recent infection
4 fold rise in antibody titre in complement fixation test
Urease producing
Treatment
Resolves spontaneously
Penicillins and cephalosporins are inactive due to lack of cell wall
Macrolide ( Erythromycin/ Tetracycline)

Gardnerella vaginalis

Facultative gram variable rod associated with bacterial viginosis
Characterized by a malodorous vaginal discharge and clue cells, which hare vaginal epithelial cells covered with bacteria
Laboratory Diagnosis
“Whiff” test – consists of treating the vavginal discharge with 10% KOH and smelling a pungent, fishy odor is usually positive.
Trichomoniasis can also cause a positive whiff test and must be ruled out before a diagnosis of bacterial vaginosis can be made
Mobiluncus an anaerobic rod is often found in this disease as well
Treatment
Metronidazole

Parasite

Chlamydia trachomatis

Obligate intracellular parasites; Gram negative bacteria, possess rigid cell wall
Habitat is the human genital tract and is transmitted by sexual contact
Laboratory Diagnosis
Cytoplasmic inclusions seen on Giemsa-stained or fluorescent-antibody-stained smear
Glycogen-filled cytoplasmic inclusions can be visualized with iodine
PCR based assay and an ELISA using patient’s urine
Grown in cell cultures treated with cycloheximide, which inhibits host cell but not Chlamydia protein synthesis
Serologic test rarely helpful in diagnosis
Treatment
Tetracycline (Doxycycline)
Macrolide (Azithromycin)

Protozoa

Trichomonas vaginalis

Urogenital protozoan
Pear shape, flagellated trophozoites
No cysts or other forms
Transmitted sexually – attach to wall of vagina and cause inflammation and discharge
Laboratory Diagnosis
Visible in secretions
Wet mount - Motile
Treatment
Metronidazole

Fungi (Yeast)

Candida albicans

Oval yeast with a single bud
Part of normal flora of the female genital tracts
Laboratory Diagnosis
Microscopic examination reveals yeasts and pseudohyphae
Gram positive and can be visualized using calcofluor- white staining
Forms colonies of yeasts on Sabouraud’s agar
Germ tube formation and production of chlamydospores distinguish Candida albicans from other species of Candida
Serologic tests not useful
Treatment
Oral or topical antifungal agents such as nystatin or miconazole
Amphotericin B
Ketoconazole

Virus

Herpes Simplex Virus Type 2

Enveloped virus with icosahedral nucleocapsid and linear double stranded DNA
No virion polymerase
No herpes group specific antigen
Transmitted through sexual contact
Laboratory Diagnosis
Causes cytopathic effect in cell culture
Identify by antibody neutralization or fluorescent- antibody test
Rise in antibody titre can be used to diagnose a primary infection
Treatment
Acyclovir

Picture 4: Cytopathic Effect

http://www.google.com/ >cytopathic effect
http://pathmicro.med.sc.edu/lecture/images/multinuc.jpg

Identification of Bacteria