4/18/2013

1

AlZaiem Alazhari University

Faculty of Medical Laboratory Sciences

Department of Microbiology

Systemic Bacteriology course

U.Mahadi Hassan Mahmoud Bsc, Msc, MIBMS Microbiology

Hospital acquired

4/18/2013

2

4/18/2013

3

4/18/2013

4

Hospital acquired infection

Also called nosocomial infection. (noso: study of disease, comial: the area

from which infection acquired).

It’s infection which the patient acquires

during his stay in hospital or after he leaves the hospital.

Nowadays, it is very important and it cost

life and money.

4/18/2013

5

Infection spread need three factors:

Endogenous or auto-infections (from

normal flora of the same patient e.g.

E. coli, Staph… etc. Exogenous from many sources of

hospital environment (e.g. from doctor or nurses).

1. Source of the organism:

4/18/2013

6

2. Susceptible host:

There are many factors that make the patient susceptible to infection, such as:

Surgery because it break the first defense line.

Catheters- canulation-drug in using .

Drugs that inhibit the normal flora.

Drugs that causing immunosuppressant

(Cortisol) organ transplantation.

3.Route of Transmission

4/18/2013

7

Causative agent: UTI:

E. coli, drug resistant G-ve bacilli (Klebsiella, Serratia macroscus) &

Pseudomonas usually followed the

catheterization.

Usually HAI start as a local infection and

then complicated to septicaemia, so fever

is the most important symptoms

Causative agent:

RTI: Acquired in patient with mechanical

ventilation or comatose patient (because many mechanical procedure done to him).

Klebsiella, drug resistance G-ve bacilli,

Enterococci, Legionella and Pseudomonas.

4/18/2013

8

Causative agent:

Skin and wound infection: S. aureus (mainly), Pseudomonas C. perfringens and Bacteroids & drug

resistance G-ve bacilli.

Important strain of Staph that causes

HAI (methicillin resistant S. aureus ).

Causative agent:

Foreign bodies related infections:

Include catheter-canulation-tubes.

Serious infection caused by non-

pathogenic organism, as S. ablus,

diphtheroides, Candida.

4/18/2013

9

Causative agent:

GIT infections:

Can be caused by different types of

organisms that cause GITI. Important HAI is C.difficile (toxigenic Clostridia) cause

serious

infection

called Pseudomembraneous colitis and some time

called antibiotic associated diarrhoea. Also can be cause by S. aureus or Candida

albicans .

Causative agent:

Infection through the blood product:

Most important HIV, HB virus.

4/18/2013

10

The role of the lab in HAI:

Isolation and identification of the

causative agent.

Sensitivity testing to the causative agent.

Detection of the reservoir(source of

infection).

Typing for epidemiological studies

(identification of the organism to the

strain levels.

Collection of specimens:

Persons: From all people on ward (patients and workers in hospital staff). Take specimen from skin, hair, throat and

nose. Moist the swab before collect hair swab by sterile D.W. The best part of the skin to

collect specimen from back of the wrist.

Furniture: floor, equipment by using moisture swabs.

4/18/2013

11

Collection of specimens:

Sample from textiles (cotton, gauze). Take small pieces by sterile forceps and then press

it on the surface of agar plate.

Lotions (fluid): amount of fluid added to

peptone water, then subculture from it. From air: by one of the following methods:

Settle plates (exposed BA plates): Put Petri dishes containing an agar medium on known surface and left open for a measured period of

time. Large bacteria carrying dust particles settle on the medium.

Collection of specimens:

Slit sampler (air slitter): it drawn in air from the environment (by -ve pressure)

at the surface of an agar plate.

Slit sampler

4/18/2013

12

Air centrifuge.

Collection of specimens:

Surface air system (SAS).

4/18/2013

13

Settler plates:

Advantage: simplicity.

Disadvantages:

Measure only the rate of deposition of large

particles from air, not the total number of large

and small bacteria carrying particles

suspended in it.

Slit sampler:

Advantage: it gives count of organism in amount of air per hours (sensitive).

Disadvantage: Noisy. Incubation: in all HAI incubate some plates

aerobically and others anaerobically

4/18/2013

14

Precautions:

4/18/2013

15

Precautions:

Wear full length plastic coat (best to be

disposable).

Wear gloves.

Use mask.

Hat.

Over shoes.

4/18/2013

16

Nails

Rings

Hand creams

Cuts & abrasions

“Chapping”

Skin Problems

THANK YOU FOR ATTENTION