Seminario Biologia molecular, tercer semestre de medicina, universidad pontificia bolivariana

1. Maria Jose Martinez Betancur
Tercer semestre- Biologia
molecular
Universidad pontifica bolivariana

2. Serratia marcescens
Rod-shaped Gram negative bacteria or bacilli .
This is a facultatively anaerobic microorganism,
meaning it can grow in the presence or
absence of oxygen.
DEFINITION
Fever
frequent urination
dysuria
Pyuria
SYMPTOMS
pain upon urination
arrhythmia
breathe difficulty
infections in the biliary tract

3. The milk that cause the out
break was given by a donor to
the hospital milk bank
Pasteurization iis a process where
the milk is heated for 30 minutes at
63ºC, the objective is to kill
pathogenic bacterias and prevent
diseases.
The hosting of photogenic bacterias in
a breast pump is caused by a lack of
cleaning and disinfection in the bump
Infected
breast pump
Unpasteurized
Contaminated milk

4. Objective
INVESTIGATION OF THE
ORIGIN OF A SERRATIA
MARCESCENS OUTBREAK
IN A NEONATAL INTENSIVE
CARE UNIT.

5. 10 micro liters were planted in BD Columbia with 5%
sheep blood and Mac donkey water # 3: it´s a
selective culture medium to isolate bacteria such as
gram-negative bacilli in products for human and
animal consumption, and incubated at 37º of 24-
48hs, to identify the strain was done by
spectroscopy: studies the interaction between
electromagnetic radiation and an object with
absorption or emission of energy
Microbiogical testing of
milk samples

6. Pulsed-field gel
electrophoresis
The electrophoresis try was made to make sure about the
origin of the outbreak with the suspected donor milk and
Serratia from the index cases 2-5. With the try we separate
DNA or RNA they are push by an electrical field through a
gel that contains smalls pores.

7. In the graph we can see the dates
in which the colonization or
infection by Serratia occurred, of
the 17 patients studied only 1 was
infected and colonizated, the
other 16 were colonized, 1 of
these babies died And 1 was
negative for Serratia.
The colonizations and infection of
patients 2, 3, 4,5, 6 ,7, 8 and 16
had a time range of 2 to 3 months
The patients 1,9,10,11,12, 14,15,16
were colonized in a time range of 1
month to 1 month and a half
Results

8. Results
For 15 of the 17 patient-derived
isolates and the 2 isolates from the
suspected donor milk, a whole-
genome analyses were performed.
Also included were 4 unrelated
samples from Hannover Medical
School (MHH 1–4) as controls.
As we can see in the photo is showed
that in average most of the patients
were infected in the same way, milk
donor, the isolate of the case 14 show
a nucleotide difference

9. Discussion:

10. CONCLUSSION:
In order to prevent a pathogenic
bacteria in milk banks is important
to make sure about the clean an
disinfection process of the
pumps and the person in charge
of providing that milk to the
babies.
molecular biology methods make
easy knowing what cause the
outbreak in the hospital and the
relationship between the bacteria
spread. .