In article <386t07$qhe at mserv1.dl.ac.uk>, "RICHARD A. MURPHY 312-996-8630"
<U14663 at UICVM.UIC.EDU> writes:
<In reading the answers to this request I keep wondering what the
ORIGINAL problem is/was - the situation requiring the separation of
the two organisms in the mixture. Could a method other than "picking
up a bacterium" be of use?
I'm not saying that that isn't the way to solve the problem for the
person making the request but I keep wondering if some selective medium
might be the answer to the problem of isolating a particular organism
that would appear to be in low proportion to the other members of the
group. Knowing the names of the bacteria, if they are known, might help.
Dick>
Sorry. The problem is a very sick patient with prostatitis. During last
attack of acute prostatitis he became septic with fever, rigors and had 4
of 5 blood cultures positive for Enterobacter Cloacae. The fact that his
Meares and Stamey Aliquot cultures, his Expressed Prostatic Fluid, his
urine cultures, or his semen cultures never grew Enterobacter Cloacae
caused me to review the cultures and procedure. It turns out that the
consulting Urologists had never done a gram stain of the Expressed
Prostatic Secretions or the Semen. On routine semenanalysis they do not do
a bacterial count or go beyond 200x power total. Of all the thirty some
cultures he has had usually coagulase negative staph grew out as
hemolyticus or epidermidis most often. Other bacteria grew out but never
in any consistant fashion: E. Coli once, Enterococcus once,
propionibacterium acnes, peptostreptococcus assaccharalyticus
strep viridans, staph epi #2 (a second strain) etc. I need to figure out
if there is one pathogen or more than one. When I do gram stains of
semen, I see loads of cocci, and few rods of different shapes. I have
seen one phagocytized rod. It all seems to go back to the age old problem
of identifying the pathogen in a sample that has to be collected
contaminated by urethral flora. After seeing this on gram stain I think
that if Enterobacter Cloacae is really present as the pathogen, then the
cultures are being overgrown by Staph as the cocci are so numerous in
comparison. I would like to separate the rods out and culture them to see
if I can give the patient a better chance. After learning from all these
posts the first thing I will do is get a specimen to a reference lab for
serial dilution to culture for aerobes and anaerobes. Then I will
consider PCR, the Optical trap, and Immunomagnetic enrichment. If anyone
has a lab that is willing to try any of these things let me know. It
turns out that the culturing technique known as the Meares and Stamey 4
glass test was developed in 1969 and has never been validated or improved
upon in 25 years, and the sensitivity is thought to be low. The disease
is still enveloped in controversy, and meanwhile I have sick patients.
Thanks.
