Starting today, Tuesday, November 15th, the microbiology laboratory will institute new testing for stool pathogens and agents of meningitis/encephalitis.  Both tests are multiplexed PCR panels covering a large number of pathogens at once with a rapid turnaround time (<6 hours).  The meningitis/encephalitis panel will be an adjunct to bacterial and fungal culture.  The enteric pathogen panel replaces culture and tests for specific pathogens listed at the bottom of this broadcast.

Key Points:

ENTERIC PATHOGEN PANEL (EPIC LAB8513)

• Only stool on FecalSwabs (Stores #105117) is acceptable for testing.
• C. difficile testing is not performed with this panel.  C. difficile testing requires raw stool, not a FecalSwab.
• Aeromonas is a rare cause of gastroenteritis in Iowa.  A new culture for Aeromonas is available for patients with exposure to contaminated water.  This can be performed from the same FecalSwab as the PCR panel.
• Susceptibility testing will be automatically performed where necessary.

MENINGITIS/ENCEPHALITIS PANEL (EPIC LAB8514)

• The meningitis/encephalitis panel does not replace culture for bacteria and fungi. The PCR panel is not comprehensive and does not provide susceptibility testing.  Test results should be interpreted in the context of patient factors and other laboratory testing such as cell count, protein and glucose. There are therefore now two approaches to diagnosis of meningitis/encephalitis:
  1) Order the M/E panel; Gram stain and bacterial culture will be automatically performed.  This is generally preferred because of the rapid turnaround time of the new panel.
  2) Order aerobic culture alone, with an appropriate source selected as before.  Order PCR testing separately; all prior individual PCR testing will remain available.  This is the approach for CSF obtained from shunts and traps: the M/E panel cannot be performed on these specimens.

• Cryptococcus is inefficiently detected by PCR and antigen testing and culture are preferred for its detection.

Tests performed on each panel:

MENINGITIS/ENCEPHALITIS PANEL
BACTERIA:
Escherichia coli K1 (non-K1 strains are not detected)
Haemophilus influenzae
Listeria monocytogenes
Neisseria meningitidis (unencapsulated strains are not detected)
Streptococcus agalactiae (a.k.a GBS or Group B Streptococcus)
Streptococcus pneumoniae

VIRUSES:
Cytomegalovirus (CMV)
Enterovirus (includes Coxsackie, Echo, and others)
Herpes simplex virus 1 (HSV-1)
Herpes simplex virus 2 (HSV-2)
Human herpesvirus 6 (HHV-6)
Human parechovirus
Varicella zoster virus (VZV)

FUNGUS:
Cryptococcus neoformans/gattii (inferior to antigen detection and culture, orderable separately)

ENTERIC PANEL
BACTERIA:
Campylobacter, Plesiomonas shigelloide, Salmonella species, Vibrio species, and Yersinia enterocolytica
Toxigenic E. coli (e.g. E. coli O157) and Shigella
Diarrheagenic "travellers' diarrhea" E. coli (EAEC, EPEC and ETEC)

PARASITES:
Cryptosporidium, Cyclospora cayetanensis, Entamoeba histolytica, and Giardia

VIRUSES:
Adenovirus 40/41, Astrovirus, Norovirus GI/GII, Rotavirus, and Sapovirus

Questions concerning this broadcast can be directed to Bradley Ford, MD, PhD, Medical Director of Microbiology; (ext. 6-2990, bradley-ford-1@uiowa.edu).