Casella CEL Airborne bacteria sampler User Manual

BACTERIA SAMPLER
User Manual

October 2002

BACTERIA SAMPLER

Users Handbook

HB 3109-05

COPYRIGHT

The copyright in this document which contains proprietary information is

vested in CASELLA CEL LIMITED. The contents of this document must not

be used for purposes other than for which it has been supplied or reproduced

or disclosed wholly or in part without the prior written permission of

CASELLA CEL

CASELLA CEL
Regent House
Wolseley Road
Kempston
Bedford, MK42 7JY
U.K.
Phone: [phone]
Fax: [phone]
E-Mail: [e-mail]
Web: www.casellacel.com

CASELLA USA
17 Old Nashua Road #15
Amherst
NH 03031
U.S.A.
Toll Free: [phone]
Fax: [phone]
E-mail: [e-mail]
Web: www.casellausa.com

Contents

BACTERIA SAMPLER

User Manual

CONTENTS .............. Page No.

1. INTRODUCTION & APPLICATION . . . . . . . . . . . . . . . . . 3

2. DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.1 Other Equipment Required . . . . . . . . . . . . . . . . 4

3. PRINCIPLES OF OPERATION . . . . . . . . . . . . . . . . . . . . 5

4. SAMPLER ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . 6

5. OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5.1 Preparation of sampling media . . . . . . . . . . . . . . . 7

5.2 Location of the sampler . . . . . . . . . . . . . . . . . . 7

5.3 Preparation for sampling . . . . . . . . . . . . . . . . . . 7

5.4 Selection of turntable rotation speed . . . . . . . . . . . 8

5.5 Selection of flow rates . . . . . . . . . . . . . . . . . . . 8

5.6 Commencement of sampling . . . . . . . . . . . . . . 10

5.7 Sampling times . . . . . . . . . . . . . . . . . . . . . . 10

5.8 Completion of sampling . . . . . . . . . . . . . . . . . 11

6. THE SELECTION OF SAMPLING CRITERIA . . . . . . . . . . . 12

7. CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

8. MAINTENANCE & SERVICING . . . . . . . . . . . . . . . . . . 14

9. TECHNICAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . 15

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BACTERIA SAMPLER
User Manual

Introduction

1. INTRODUCTION & APPLICATION

Airborne bacteria have for a long time been recognised as the causal agents
of infectious diseases, particularly those of the respiratory tract. In clinical
environments there is the possibility that such organisms can lead to serious
infections of wounds and burns and result in infection during surgical
operations. The production of many foods (especially dairy produce) and
pharmaceutical products can be contaminated by micro organisms, one
potential route being airborne bacteria, resulting in the loss of product. In
addition there is growing interest in healthy working environments,
particularly in large office complexes. In such instances air quality is a major
consideration and the level of airborne bacteria present an issue. As a result
there are a range of areas in which the concentration of airborne bacteria
may require evaluation, as well as the identification of the species present
and their time of occurrence.

The Casella Airborne Bacteria Sampler has been developed to facilitate the
determination of airborne bacteria concentrations and types, by the collection
of airborne bacteria on agar plates, which can be incubated so that individual
bacteria form colonies which can then be counted by standard plate counting
techniques. The sampler is designed for ease of use and is based on an
original design developed by Drs. Bourdillion, Lidwell and Thomas of the
Medical Research Council.

References to this instrument have been made in the

bacteriological standards for air in ultraclean operating rooms

by W.Whyte, E.J.L.Lowbury, and R.Blowers in the Journal of Hospital
Infection (1983) 4, 133-139.

Suggested

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Descriptipn

BACTERIA SAMPLER

User Manual

2. DESCRIPTION

The Airborne Bacteria Sampler consists of the following components :

1. A pump unit, with air flow control,

2. An airborne bacteria sampling unit, comprising control box/turntable
(with mains power cable), and sampling head,

3. An air intake nozzle, which fits into the sampling head,

4. Flexible hose, for attaching the pump unit to the sampling unit,

5. An electric cable, which plugs into the sampling unit and pump to
supply power to the latter,

6. Three blanking-off strips, for closing air flow slits.

If any of the above components are not present with the instrument supplied,
please contact CASELLA CEL.

2.1 Other Equipment Required

In addition to the Airborne Bacteria Sampler, standard microbiological
equipment is required including :

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BACTERIA SAMPLER
User Manual

1. Sterile petri dishes (minimum internal diameter 14cm, maximum
external diameter 16cm), for holding the agar media,

2. Suitable agar media, for collecting and growing the bacteria,

3. An Autoclave, for preparing and sterilising the agar media,

4. A Laminar flow cabinet, for preparing agar plates,

5. An Incubator, for growing the bacteria on the plates into colonies
after sampling,

6. Plate counting facilities, for enumerating the colonies after incubation.

In order to minimise the risk of contamination of the sampling media before
and after sampling, standard microbiological practices should be adopted.

Principles of Operation

3. PRINCIPLES OF OPERATION

In order to determine the concentration of airborne bacteria, air is drawn into
the sampling unit at a controlled rate, through the air inlet nozzle. The air is
then passed at a high speed through a narrow slit (or slits) located in the
sampling head (which covers the turntable). Two millimetres below the slit
(or slits) a petri dish containing agar is positioned on a turntable and the air
flowing through the slits impinges on the media. Due to the high velocity of
the air and the moist agar surface, airborne micro organisms are captured on
the media. The agar jelly, contained in the petri dish, is then incubated at a
controlled temperature, so that the originally invisible bacteria from the nuclei
of bacterial colonies, become visible to the naked eye and can therefore be
enumerated.

During sampling the petri dish is rotated on the turntable under the slit (or
slits), spreading the bacteria evenly across the surface of the agar to facilitate
the counting of bacterial colonies and to enable the timing of bacteria
deposition to be established.

To achieve satisfactory sampling over a wide range of airborne bacteria
concentrations, a range of air sampling flow rates are available which are
controlled by the number of slits in use and the speed of the pump.

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