Microbiology Test

Abscess, Aerobic and Anaerobic Bacteria culture

Test Abscess, Aerobic and Anaerobic Bacteria culture

Indication Identification of bacteria causing abscess and provide therapy

Normal Range No growth of aerobic or anaerobic bacteria.

Sample Fluid, pus, or abscess material

Test Method Aerobic and anaerobic culture

Related Tests Cerebrospinal Fluid Anaerobic culture, Fine Needle Aspiration, Susceptibility Testing, Wound culture.

Acid Fast stain

Test Acid Fast stain

Indication The staining is used to detect the presence of mycobacteria, monitor therapy against mycobacterium, effective diagnosis of mycobacterial infection.

Normal Range No acid fast bacteria. Positive smears are quantitated and reported as 1+ (3-9 bacteria in entire smear), 2+ (>10 in entire smear), or 3+ (1 or more bacilli per field) acid fast bacteria seen.

Sample Fluid, pus, or abscess material

Test Method Acid fast stain – Ziehl-Neelsen or fluorochrome stain

Related Tests Mycobacteria by DNA probe, Skin Test, Tuberculosis.

Actinomyces culture

Test Actinomyces culture

Indication Actinomycosis is a chronic progressive suppurative disease forming multiple abscesses, draining sinuses, and dense fibrosis.

Normal Range No actinomyces isolated.

Interpretation Actinomyces produce chronic suppuration with formation of multiple draining sinuses. The presence of sulfur granules is highly suggestive of Actinomyces infection. Granules are detected on the gauze pad covering a draining sinus.

Sample Exudate, draining sinus collection.

Test Method Anaerobic culture

Related Tests Acid fast stain, Biopsy, Endometrium culture, Nocardia culture.

Bacterial Antigens

Test Bacterial Antigens

Indication Qualitative identification for the presence of antigens of Haemophilus influenzae, Streptococcus pneumoniae, Neisseriae meningitidis. The test is used to detect bacterial antigens in CSF for the rapid diagnosis of meningitis.

Normal Range Negative

Interpretation Bacterial antigens may be detected despite previous antibiotic therapy, immunologic methods.

Sample Cerebrospinal fluid, serum

Test Method Latex agglutination

Related Tests Cerebrospinal fluid culture, Cryptococcal Antigen titer, Viral culture, Central Nervous system.

Blood culture, Aerobic and Anaerobic

Test Blood culture, Aerobic and Anaerobic

Interpretation Interpretation of Positive blood cultures

Sample Venous blood

Test Method Early subculture in aerobic bottle, blood agar and chocolate agar. Antimicrobial susceptibility

Blood culture, Brucella

Test Blood culture, Brucella

Indication Test used to diagnose brucellosis

Normal Range No presence of Brucella species

Interpretation The bacteria brucella appears as a small, slow growing white colony. It is a gram negative coccobacillus

Related Tests Blood culture, Aerobic and Anaerobic

Bordetella pertussis Nasopharyngeal culture

Test Bordetella pertussis Nasopharyngeal culture

Indication The test is used to isolate and identify B. pertussis, and B. parapertussis, establish the diagnosis of whooping cough.

Normal Range No B. pertussis or B. parapertussis isolates.

Sample Nasopharyngeal swab, cough plate.

Test Method Culture on chocolate agar/blood agar.

Related Tests Bacterial serology, Nasopharyngeal culture.

Botulism

Test Botulism

Indication Food poisoning. The test is used to diagnose infant botulism, sudden death syndrome, floppy baby syndrome, classic botulism in adults.

Normal Range No toxin identified, no clostridium botulinum isolated.

Sample Vomit, serum, stool, gastric washings, cerbrospinal fluid or autopsy tissue, food samples.

Test Method Toxin neutralization test in mice.

Bronchoalveolar Lavage

Test Bronchoalveolar Lavage

Indication The test is used to identify the etiology of potentially treatable pulmonary infections.

Normal Range Normal total cell count: 4-23X106; differential: 95% alveolar macrophages, 3% lymphocytes, 1% polymorphonuclear cells, 0.2% eosinophils; <104 CFU/mL aerobic bacteria.

Sample Bronchoalveolar lavage

Test Method Bronchoalveolar lavage

Burn culture

Test Burn culture

Indication Identify bacteria present in the skin specimen from burn patient.

Normal Range No growth to <105colonies/g of tissue.

Interpretation The use of quantitative burn cultures has little value in identifying patients with invasive infection and in differentiating those who are not likely to develop burn wound sepsis. The bacteria most frequently recovered from burn wounds in Pseudomonas aeruginosa.

Sample Viable tissue, not eschar.

Test Method Bacterial and fungal culture

Related Tests Wound culture

Cell wall defective bacteria culture

Test Cell wall defective bacteria culture

Indication The test is used to detect bacteria which have developed a cell wall defective structure due to drug therapy.

Normal Range No growth

Sample Body fluid (blood, spinal fluid, pleural fluid or urine) or tissue.

Test Method Culture in hypertonic medium.

Cerbrospinal fluid culture

Test Cerbrospinal fluid culture

Indication The test is to isolate and identify pathogenic organisms causing meningitis, shunt infection, brain abscess, subdural empyema, cerebral or spinal epidural abscess, bacterial endocarditis with embolism.

Normal Range No growth

Interpretation The gold standard for the diagnosis of bacterial meningitis is the isolation of a bacterium from the cerebrospinal fluid. Diagnosis of meningitis is made by examination and culture of CSF. Nucleated blood cell count, differential, Gram stain, CSF glucose, and CSF protein are needed. Blood cultures are often positive with meningitis.

Sample Cerebrospinal fluid

Test Method Aerobic culture

Related Tests Bacterial antigens, Blood culture, Cerebrospinal fluid Analysis, Cerebrospinal fluid anaerobic culture.

Cerebrospinal fluid anaerobic culture

Test Cerebrospinal fluid anaerobic culture

Indication Anaerobic culture is indicated only if brain abscess, subdural empyema, or epidural abscess is suspected or in the presence of a primary anaerobic infection at another site which is suspected of involving the central nervous system.

Normal Range No growth

Sample Cerebrospinal fluid or aspirate of fluid from intracranial lesion.

Test Method Anaerobic culture

Related Tests Cerebrospinal fluid culture, Viral culture.

Clostridium difficile Toxin Assay

Test Clostridium difficile Toxin Assay

Indication Diagnose antibiotic related colitis caused by C. difficle toxin. Antibiotic associated pseudomembranous colitis is produced primarily by toxigenic C. difficile.

Normal Range Presence of toxin is suggestive of disease. Isolation of organism may occur in a small percentage of normal adults and in normal newborns. Isolation of the organisms without demonstration of toxin production is a nonspecific finding since all isolates are not toxigenic.

Sample Stool or proctoscopic specimen

Test Method Latex agglutination

Conjunctival culture

Test Conjunctival culture

Indication The test is to isolate and identify potentially pathogenic organisms.

Normal Range Normal flora of the eye

Sample Eye swab

Test Method Aerobic culture on blood and chocolate agar

Related Tests Adeno virus antibody titer, Adenovirus culture.

Conjunctival fungus culture

Test Conjunctival fungus culture

Indication The test is to confirm presence of keratomycosis

Normal Range No growth

Sample Scrapings of corneal ulcer, washings of lacrimal duct

Test Method culture Sabouraud’s medium, Brain heart infusion agar.

Related Tests Conjunctival culture, Fungus smear

Cryptococcal antigen titer

Test Cryptococcal antigen titer

Indication Test investigates subacute or chronic meningitis, investigate CSF containing cells without Gram stain positivity for bacteria, establish the diagnosis of Cryptococcus neoformans infection, follow response to therapy.

Normal Range Negative

Interpretation Presence of cryptococcal capsular polysaccharide is indicative of Cryptococcosis.

Sample Serum or cerebrospinal fluid

Test Method Latex agglutination

Cryptosporidium Test

Test Cryptosporidium Test

Indication This test is done to differentiate work up of diarrhea, particularly in immune compromised hosts and suspected AIDS patients, establish the diagnosis of cryptosporidiosis by demonstration of the oocysts.

Normal Range Negative

Sample Stool

Test Method Phase contrast microscopy

Ear culture

Test Ear culture

Indication Test is used to determine the etiologic agent of otitis externa or otitis media.

Normal Range Normal flora of the healthy ear – Staphylococcus aureus, Staphylococcus epidermidis, Corynebacterium sp.

Sample Aspirate from Otitis externa.

Test Method Aerobic and anaerobic culture

Endometrium Culture

Test Endometrium Culture

Indication To isolate and identify aerobic and anaerobic organisms present in the endometrium

Normal Range No growth

Sample Scrapings, aspirates, or swabs taken from endometrium

Test Method Aerobic and anaerobic culture

Related Tests Abscess, Chlamydia trachomatis

Helicobacter pylori Testt

Test Helicobacter pylori Testt

Indication Establish the presence and possible role of Helicobacter ylori in chronic gastric ulcer, active gastritis and duodenal ulcers.

Normal Range Negative for urease activity, negative culture, biopsy negative for gastritis and negative for H. pylori.

Interpretation Most peptic ulcers related to H. pylori are curable.

Sample Gastric mucosal biopsy

Test Method Urease test, Culture

India Ink Preparation

Test                                       India Ink Preparation

Indication                            Establish the presence of Cryptococcus sp or other fungi.

Normal Range                   No cryptococcus identified

Sample                                 Fungal specimen

Test Method                      Wt mount with india ink for contrast

Related Tests                     Cerbrospinal fluid culture, Cryptococcus antigen titer, KOH preparation

Intravascular Device Culture

Test Intravascular Device Culture

Indication Culture of intravascular devices should be limited to patients who have laboratory confirmed bacteremia or who appear clinically septic.

Normal Range Roll plate cultures: < 15 colonies, sonicated specimen < 10 4 colonies.

Sample I.V. catheter tip, foreign body, blood collected through catheter.

Test Method Roll plate semi quantitative cultures, Quantitative sonication method, Comparative quantitative cultures.

KOH preparation

Test KOH preparation

Indication Determine the presence of fungi in skin, nails or hair

Normal Range No fungus elements identified

Sample Fungal specimen

Test Method 10% KOH with gentle heat, alternately 20% KOH or 10% KOH and 40 % dimethyl sulfoxide (DMSO)

Related Tests Fungus smear, Gram stain, Indian ink preparation.

Legionella culture

Test Legionella culture

Indication Isolate and identify Legionella sp

Normal Range No Legionella recovered

Interpretation Infections caused by Legionella – Pneumonia, Empyema, Sinusitis, Prosthetic valve, endocarditis, Wound infection, Bowel abscesses, Brain abscesses, Lung abscesses, Myocarditis, Pericarditis, Peritonitis, Renal abscesses, Vascular graft infections, Pontiac fever, Encephalopathy, Myocarditis, Without pneumonia.

Sample Lung tissue, other body tissue, pleural fluid, other body fluid, bronchoalveolar lavage, bronchial brushing, sputum.

Test Method Culture on selective and nonselective media

Related Tests Sputum culture, Legionnaires disease antibodies

Leptospirosis, Darkfield Examination,

Test Leptospirosis, Darkfield Examination,

Indication The test is used to determine the presence of Leptospira for the diagnosis of Weil’s syndrome, hemorrhagic fever with renal syndrome, atypical pneumonia syndrome, aseptic meningitis, and myocarditis including cardiac arrhythmias.

Normal Range No presence of Leptospira species

Interpretation Dark field microscopy is used to demonstrate leptospires in specimens in which a high concentration of organisms is present.

Sample Urine, serum, cerebrospinal fluid

Test Method Dark field microscopy

Related Tests Leptospira culture, Leptospira serodiagnosis.

Methylene blue stain

Test Methylene blue stain

Indication The test assists in the differential diagnosis of diarrheal disease.

Normal Range No presence of yeast, cocci in clusters or leukocytes

Sample Fresh random stool, rectal swab

Test Method Smear of stool with one drop of methylene blue, coverslip and observe the presence of leukocyte.

Related Tests Stool culture, Clostridium difficile Toxin assay

Nasopharyngeal culture

Test Nasopharyngeal culture

Indication Isolate and identify potentially pathogenic organisms. Nasopharyngeal culture may reflect infection of tonsils, oropharynx, nasopharynx, and sinuses. Useful in identifying carriers of S. aureus and N. meningitidis.

Normal Range Normal nasopharyngeal flora

Sample Nasopharyngeal swab.

Test Method Aerobic culture

Neisseria gonorrhoeae culture

Test Neisseria gonorrhoeae culture

Indication Isolate and identify Neisseria gonorrhoeae, establish the diagnosis of gonorrhea.

Normal Range No Neisseria gonorrhoeae isolated.

Sample Body fluid, discharge, pus, swab of genital lesions, urethral discharge, endocervix, throat swab, rectal swab.

Test Method Culture on selective media. DNA probes, Monoclonal antibodies, Enzyme immunoassay.

Related Tests Penicillinase Test, RPR, VDRL, Neisseria gonorrhoeae smear

Neisseria gonorrhoeae smear

Test Neisseria gonorrhoeae smear

Indication Detect gram negative intracellular diplococci resembling N. gonorrhoeae

Normal Range Negative

Sample Urethral swab

Test Method Gram stain

Related Tests Chlamydia trachomatis, Gram stain, Neisseria gonorrhoeae culture

Nocardia culture

Test Nocardia culture

Indication Establish the diagnosis of nocardiosis or mycetoma, identify its pathogenic agent.

Normal Range No nocardia sp isolated

Sample Pus, tissue, cerebrospinal fluid or other body fluid, aspirate, sputum.

Test Method Aerobic culture on blood agar and Lowenstein Jensen media with no antibiotics. Infections may be acute, sub-acute, or chronic and they may be disseminated or localized to cutaneous sites or the respiratory tract.

Related Tests Acid fast stain, Actinomyces culture, Sputum culture.

Ova and Parasites

Test Ova and Parasites

Indication Establish the diagnosis of parasitic infestation

Normal Range No parasites seen

Sample Fresh or preserved random stool or duodenal aspirate. If pinworm is suspected, a scotch Tape preparation should be submitted to the laboratory instead of stool.

Test Method Wet mount and trichrome stain, Immunofluorescence, Counterimmunoelectrophoresis, Enzyme linked immunosorbent assay.

Related Tests Ascariasis, Cryptosporidium procedure, Echinococcosis, Entamoeba histolytica, Enterovirus culture, Filariasis, Pinworm preparation, Rotavirus, Stool culture.

Penicillinase Test

Test Penicillinase Test

Indication The test is used for rapid detection of beta lactamase production from isolated colonies of Haemophilus influenzae, Neisseria gonorrhoeae, Moraxella catarrhalis, S. aureus, and enterococci sp.

Sample Haemophilus infeluenzae, Moraxella catarrhalis, Neisseria gonorrhoeae, enterococci, Sttaphylococcus aureus, gram negative anaerobic rods.

Test Method Acidimetric method

Related Tests Neisseria gonorrhoeae culture, Susceptibility testing.

Pinworm Preparation

Test Pinworm Preparation

Indication Detect cases of pinworm infestation (enterobiasis), Enterobius vermicularis parasitic infestation

Normal Range No pinworm eggs identified

Interpretation The most satisfactory means of diagnosing pinworm infection is by the recovery of eggs or female wroms from the perianal region.

Sample Scotch Tape slide preparation of perianal region

Test Method Microscopy

Related Tests Ova and parasites

Serum Bactericidal Test

Test Serum Bactericidal Test

Indication Determine the maximum bactericidal dilution or serum bactericidal dilution of serum or body fluid after administration of antibiotics.

Normal Range Peak bactericidal activity should be observed at >1:8 dilution, trough at >1:2.

Interpretation The titer is useful in monitoring total therapeutic effect. It is used to evaluate therapy in endocarditis, osteomyelitis, and suppurative arthritis. Serum bactericidal titers of >1:8 are often recommended for the optimal treatment of these infections.

Sample Peak and trough serum from patient and bacterial isolate causing infection.

Test Method Serial dilution of patients serum with Mueller Hinton broth.

Related Tests Antibiotic level

Skin fungus culture

Test Skin fungus culture

Indication Isolate and identify fungi

Normal Range No growth

Interpretation Diseases caused by fungi: Superficial mycoses – Piedra, Tinea nigra, Tinea versicolor. Dermatomycoses – Oncyhomycosis, Tinea captis, Tinea corporis, Tinea pedis, Tinea cruris. Candididasis – Thrush, Diaper dermatitis, Paroncyhia, Congenital candidiasis, Mucocutaneous candididasis.

Sample Skin scrapings, exudates, nail clippings, whole nail, debris, under nail, hair.

Test Method Aerobic culture on selective media.

Skin Test, Tubeculosis

Test Skin Test, Tubeculosis

Indication Test for delayed hyersensitivity reaction to tuberculin.

Normal Range No reaction.

Test Method Tuberculin test

Related Tests Acid fast stain, Mycobacterium test

Sputum culture

Test Sputum culture

Indication Isolate and identify potentailly pathogenic organisms present in the lower respiratory tract, identify isolates responsible for pneumonia, bronichitis, bronchiectasis. Presence or absence of normal upper respiratory flora is often reported.

Normal Range Normal upper respiratory flora, Tracheal aspirate and bronchscopy speciemen should not have any growth.

Sample Sputum, tracheal aspiration, bronchoscopy specimen, transtracheal aspirate.

Test Method Aerobic culture.

Related Tests Blood culture, Bordetella pertussis, Bronchoalveolar lavage, Gram stain, Legionella culture, Mycoplasma pneumoniae, Sputum cytology.

Sputum fungus culture

Test Sputum fungus culture

Indication Establish the presence and identity of potentially pathogenic fungi.

Normal Range No growth

Sample Sputum, tracheal aspiration, bronchoscopy specimen, transtracheal aspirate.

Test Method Culture on selective media

Related Tests Aspergillus, Bronchoalveolar lavage, Cryptococcus test, fungus smear, Histoplasmosis, KOH preperation. Nocardia culture, sputum culture, throat culture.

Sputum Mycobacteria culture

Test Sputum Mycobacteria culture

Indication Diagnose pulmonary tuberculosis or other Mycobacterium sp from expectorated sputum, induced sputum, nastracheal aspiration, gastric aspiration

Normal Range No growth

Sample Sputum, tracheal aspiration, bronchoscopy specimen, transtracheal aspirate.

Test Method Culture on slective medium – Lowenstein-Jensen and Middlebrook 7H11.

Related Tests Acid fast stain, Bronchial washing, Bronchoalveolar lavage, Nocardia culture, Sputum culture, Viral culture.

Sterility culture

Test Sterility culture

Indication Confirm that adequate sterilization conditions have been attained.

Physiology Biological indicators must be used at least once weekly with the steam autoclaves and with every load with the ethylene oxide sterilizer.

Normal Range No growth in test strips

Sample Three strips (one control and two test strips)

Test Method Indicator strips impegrenated with spores of Bacillus stearothermophilus are used with steam autoclaves

Stool culture

Test Stool culture

Indication Screen for pathogenic bacterial organisms in the stool, diagnose typhoid fever, enteric fever, bacillary dysentery, salmonella infection.

Normal Range Negative for pathogens

Sample Stool, rectal swab

Test Method Aerobic culture on selective media.

Stool Culture, Diarrheagenic E.coli

Test Stool Culture, Diarrheagenic E.coli

Indication Establish diarrheagenic E.coli as the cause of clinical illness.

Normal Range Normal colinc flora

Sample Rectal swab, fresh stool

Test Method Culture in macconkey agar.

Related Tests Methylene blue stain, Stool culture

Stool fungus culture

Test                                       Stool fungus culture

Indication                            Establish the presence of fungi, particularly candida sp, in immunosuppresed hosts.

Normal Range                   No growth

Sample                                 Stool, rectal swab

Test Method                      Culture on selective media

Related Tests                     Fungus culture, Candida antigen, Methylene blue stain, Sputum fungus culture, stool culture.

Stool Culture, Diarrheagenic E.coli

Test Stool Culture, Diarrheagenic E.coli

Indication Establish diarrheagenic E.coli as the cause of clinical illness.

Normal Range Normal colinc flora

Sample Rectal swab, fresh stool

Test Method Culture in macconkey agar.

Related Tests Methylene blue stain, Stool culture

Susceptibility testing, Bacteria

Test Susceptibility testing, Bacteria

Indication To determine antimicrobial susceptibilityof organisms involved in infectious processes when the susceptibility of the organism cannot be predicted from its identity.

Normal Range Reported as Minimum Inhibitory Concentration (MIC). Results may be susceptible (S), Intermediate (I), Resistant

Sample Microorganism

Test Method Disc diffusion assay, Microbroth diltuion.

Related Tests Abscess, Antibiotic level.

Susceptibility testing, Fungi

Test Susceptibility testing, Fungi

Indication Determine susceptibility of isolated fungi to available therapeutic agents, predict probable clinical response

Interpretation Interpretation of in vitro susceptibility data for antifungal drugs has been hindered by the absence of standardized test criteria against fungi.

Sample Fungal specimen

Test Method Susceptibility testing

Related Tests Blood fungus culture, fungus smear, sputum fungus culture.

Syphilis, Dark field examination

Test Syphilis, Dark field examination

Indication The test determines the presence of characteristic spirochetes in lesions suspected of causing syphilis.

Normal Range No presence of Treponema species

Sample Moist serum from lesions, chancre, condyloma.

Test Method Dark field microscopy

Related Tests Automated Reagin Test, RPR, VDRL

Throat culture

Test Throat culture

Indication Isolate and identify potentially pathogenic organisms from throat, evaluate pharyngitis.

Sample Throat swab

Test Method Aerobic culture

Related Tests Antihyaluronidase Titer, Antistreptolysin O titer, Bacterial serology, Gram stain, Sputum fungus culture.

Trichomonas preparation

Test Trichomonas preparation

Indication Establish the presence of Trichomonas vaginalis.

Normal Range Negative, no trichomonads identified.

Sample Vaginal, cervical, urethral swabs, prostatic fluid, urine sediment.

Test Method Wet mount microscopic examination, pap smear.

Related Tests Cervical vaginal cytology, Genital culture

Urine culture

Test Urine culture

Indication Isolate and identify potentially pathogenic organisms causing urinary tract infection.

Normal Range No growth. Significant bacteriuria is usually considered to be 10 5 CFU/mL.

Sample Urine

Test Method Quantitative aerobic culture

Related Tests Chlamydia trachomatis, Gram stain, Urine fungus culture, Viral culture

Urine fungus culture

Test Urine fungus culture

Indication Detect and identify yeasts and fungi in urine specimens.

Normal Range No growth

Sample Urine

Test Method Culture on selective media

Related Tests Blood fungus culture, Candidiasis, fungus smear

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s