Body Fluids, Urinary Tract & Genital Tract PDF

Central Nervous System Chapter 35  Introduction Central Nervous System brain spinal cord meninges Sterile  Term s Cerebrospinal fluid (CSF) bathes brain and spinal cord clear and colorless test: culture, cell c...

Central Nervous System Chapter 35  Introduction Central Nervous System brain spinal cord meninges Sterile  Term s Cerebrospinal fluid (CSF) bathes brain and spinal cord clear and colorless test: culture, cell count, glucose & protein levels Meningitis inflammation of meninges Purulent meningitis also known as pyogenic meningitis pus in meninges usually bacteria  Term s Aseptic meningitis nonpyogenic usually caused by virus Encephalitis inflammation of brain – often caused by virus Meningoencephalitis inflammation of brain and meninges  Routes of Infection Hematogenous most common route bloodstream carrying organisms from colonized or infected site to meninges N. meningitidis colonize nasopharynx, enter blood →meningitis Contiguous spread organism spreading from infected adjacent site (sinusitis)  Routes of Infection Trauma breach CNS protective barrier skull fracture Surgery microbial contamination Shunts placed to remove fluid portal of entry  Acute Bacterial Meningitis Symptoms flu-like symptoms headache fever nausea vomiting nuchal rigidity (stiff neck) photophobia mental status changes  Causative Agents Neonates (through birth canal) E. coli other GNR (Klebsiella, Enterobacter) S. agalactiae Listeria monocytogenes Young children (6 months - 5 years) H. influenzae b N. meningitidis (meningococci) S. pneumoniae (pneumococci)  Causative Agents Older children and adults meningococci and pneumococci Elderly pneumococci, meningococci, GNR, L. monocytogenes Immunocompromised L. monocytogenes and encapsulated bacteria Shunt CN staphylococci and S. aureus  Specimen Collection Lumbar puncture  Specimen Collection Transported at RT within 15 minutes of collection STAT processing stored in incubator or at RT do not refrigerate - meningococci, pneumococci, H. influenzae  Specimen Collection 3-4 tubes collected Tube #1 chemistry – protein, glucose Tube #2 microbiology – gram stain, culture Tube #3 hematology – cell count, differential  Microbiology Processing STAT processing If >1 ml CSF→ centrifuge sediment for smear and culture Gram stain smears sensitivity 75-90% Thick smears  Culture s Media BAP, CHOC most common MAC or EMB if GNR seen in gram stained smears anaBAP if requested anaerobes rarely isolated incubate at 35-37 C in CO2  Antigen Detection Tests Available for group B streptococci, Hib, meningococci, pneumococci Should supplement, not replace, smears and cultures  Other Types of Meningitis Spirochetes T. palladum and B. burgdorferi Viral Aseptic meningitis No growth from bacterial culture Mycobacterial M. tuberculosis  Other Types of Meningitis Fungal Rarely Chronic meningitis Immunocompromised Parasitic Rarely CSF Findings Organisms Cells Dx Bacterial Usually Neutrophils Ag, culture Fungal Occasional Lymphs Stain, Ag TB Rare Lymphs PCR, stain Syphilitic No Lymphs VDRL Viral No Lymphs Serology, PCR Parasitic Rare Lymphs/Eos Serology, biopsy  Brain Abscesses Caused by NF organisms anaerobic bacteria, staphylococci, viridans, other streptococci Aspirate and biopsy materials Transported in anaerobic conditions Examined microscopically Cultured aerobically and anaerobically  Encephalitis/ Meningoencephalitis Viruses Most common Bacteria L. monocytogenes, Rickettsia, Mycoplasma, B. burgdorferi Parasites Naegleria, Acanthamoeba  Reporting Results Critical values Immediate notification Verbal communication followed by written report Body Fluids Bailey and Scott Chapter 61  Introduction – ALL STERILE Pleural fluid cover lungs lining chest cavity Peritoneal fluid abdominal cavity Pericardial fluid heart space fluid  Introduction – ALL STERILE Synovial fluid joint fluid Amniotic fluid surrounds fetus  Pleural Fluid - Thoracentesis Pleural cavity between lungs and chest wall Pleural Effusion – excess fluid Empyema – infection spreads from lungs →purulent pleural fluid Bacteria recovered from pleural fluids same organisms causing pneumonia  Peritoneal Fluid - Paracentesis Peritoneal cavity in the abdomen Primary peritonitis spontaneous bacterial peritonitis no known source of infection caused by Enterobacteriaceae, staphylococci, S. pneumoniae, viridans strep, S. pyogenes  Peritoneal Fluid - Paracentesis Secondary peritonitis known source of infection ruptured appendix, perforated bowel caused by Enterobacteriaceae, enterococci, Bacteroides, other anaerobes  Peritoneal Dialysis Fluid Dialysis fluid (dialysate) used in chronic ambulatory peritoneal dialysis (CAPD) treatment for patients with end-stage renal failure introduced into peritoneal cavity metabolic waste removed with dialysate Caused by skin flora Staph, strep, GNR, Corynebacterium spp.  Pericardial Fluid - Pericardiocentesis Pericardial space protective tissue around the heart Pericarditis usually caused by virus  Synovial Fluid – Joint Fluid Infectious/septic arthritis S. aureus is most common pathogen Also caused by streptococci, N. gonorrhoeae, H. influenzae, Bacteroides spp.  Amniotic Fluid- Amniocentesis Amnionitis- Infection of the amniotic membrane Fetal membrane rupture Can happen also when membrane is still intact Group B streptococci*, anaerobes, E. coli, Gardnerella vaginalis, Ureaplasma urealyticum  Specimen Collection Amniocentesis, arthrocentesis, pericardiocentesis, paracentesis, thoracentesis Collected by percutaneous aspiration with a needle and syringe As much fluid as possible is collected Pericardiocentesis Paracentesis  Transpor t Sterile screw-cap tubes Anaerobe transport tubes Blood culture tubes Capped syringes Transported at RT All fluids are processed STAT (short turnaround time)  Processin g Physical appearance noted Concentrated Gram stain and culture prepared from specimen sediment Urinary Tract Chapter 37  Introductio n Upper urinary tract kidneys ureters Lower urinary tract bladder urethra prostate Urinary Tract Normal Flora Sterile above urethra, NF in urethra Coag-neg staph Enterobacteriaceae Corynebacterium Anaerobic bacteria Micrococcus Yeast Streptococci Mycoplasma  Term s Urinary tract infection (UTI) Microbial invasion of urinary system Very common Bacteriuria bacteria in urine Pyuria WBC in urine  4 Types of UTIs Cystitis (lower UTI) bladder infection dysuria with frequent urination Pyelonephritis (upper UTI) kidney infection fever, pain, dysuria, frequent urination  4 Types of UTIs Acute urethral syndrome (AUS) in young women dysuria, pyuria, bacteriuria Urethritis same sypmtoms as UTI, but considered sexually transmitted  UTI Caused by endogenous flora E. coli (most common) other Enterobacteriaceae (Klebsiella) Staphylococcus saprophyticus (young women), S. aureus enterococci Pseudomonas  AUS Caused by S. saprophyticus, Enterobacteriaceae, N. gonorrhoeae, C. trachomatis  Routes of Infection Ascending route from urethra to bladder (to kidneys) Descending route carried by bloodstream to kidneys MTB and S. aureus  Epidemiolog y Predisposing factors urinary tract abnormalities enlarged prostate kidney stones instrumentation catheterization underlying medical conditions diabetes mellitus  Epidemiolog y Women most UTI occur in women short female urethra hormonal changes sexual activity pregnancy Men >60 years associated with enlarged prostate  Nosocomial Infections UTI is most common nosocomial infection in US hospitals Onset preceded by catheterization and other instrumentation  Specimen Collection & Transportation General consideration: urine inside body is sterile above urethra Contamination: urethral, vaginal, skin, fecal organisms during collection Periurethral area cleaned with mild soap and rinsed Specimen collected in sterile container Bedpans and urinals should not be used  Timin g Urine should remain in bladder as long as possible urine is good growth medium Number of colony-forming unit (CFU)/ml increases with incubation First morning specimen  Acceptable Specimens Clean-catch midstream Straight catheter Indwelling catheter Suprapubic aspirates Cystoscopy specimens  Clean-Catch Midstream Periurethral area cleaned Patient begins voiding Collects midstream specimen Fist urine passed not collected avoid NF from urethra  Straight Catheter In/out catheter urine Periurethral cleaned Catheter inserted in bladder Midstream specimen collected  Indwelling Catheter Clean catheter collection port with alcohol Aspirate specimen with needle and syringe Should not be collected from catheter bag  Suprapubic Aspirates Needle inserted through abdominal wall into full bladder Suitable for anaerobic bacteria  Cystoscopy Specimens Collected by cystosope Urine from bladder and/or ureter  Transpor t Transported at RT Cultured within 2 hours of collection If not, urine should be refrigerated Preservatives prolong RT transport time to 24 hours boric acid maintains original colony count  Unacceptable Specimens Urine catheter tips (Foley catheters) Pooled 24-hour urine Unrefrigerated or unpreserved urine (if older than 2 hours) Urine other than suprapubic aspirates for anaerobic culture  Urine Sediment Examination Urinalysis usually includes a microscopic aliquot centrifuged wet mount of sediment examined for WBC and bacteria, indicative of UTI  Chemical Methods Included with a Urinalysis, can be done separately for UTI screen leukocyte esterase test nitrate test  leukocyte esterase test Enzyme present in WBC Dipstick Positive → pyuria  Nitrite Test Nitrate normal in urine (not nitrite) Some organisms reduce nitrate nitrite Dipstick detects nitrite in urine Positive: significant bacteriuria False negative: some organism can not reduce nitrate (enterococci) False positive: specimen not properly preserved, contamination from nitrate reducing organism  Culture Media BAP Enteric agar (MAC, EMB) Other in special situations CHOC if Haemophilus suspected  Inoculatio n Cultured quantitatively on BAP agar CFU/ml is important diagnostic tool Calibrated loops that delivers 0.001 or 0.01 ml of urine Loops dipped into well-mixed uncentrifuged urine loop completely covered Streaked down center of plate and then spread over surface of agar Loops  Streaking Incubation Overnight at 35 0 C  Colony Count CFU/mL calculated if 0.01 mL loop used number of colonies on plate x 100 = CFU/mL if 0.001 mL loop used (not recommended) number of colonies on plate x 1000 = CFU/mL Colony Count Urine Culture  Worku p Factors type of specimen (voided, catherized) patient history and symptoms Voided specimens may be contaminated with NF colony count number of colony types present determining what colony is the pathogen  General Guidelines: CCMS One or two organisms, >104 CFU/ml ID and sensitivity to be performed One organism, >103 CFU/ml, symptomatic ID and sensitivity to be performed >3 organisms, no predominant type contaminated specimen, reject request new specimen  General Guidelines Suprapubic aspirates ID and sensitivity as appropriate special request - non-routine Catheterized, any count ID and sensitivity No Growth 0-999 CFU/mL present Report No growth at xx hours  One Type of Possible Pathogen 100,000 CFU/mL Probable infection ID and sensitivity  Two Types of Possible Pathogens Each >10,000 CFU/mL Possible infection ID and sensitivity on both One >10,000 CFU/mL, other