Microbiological Sampling of Air in food industry

1. MICROBIOLOGICAL
SAMPLING OF AIR
Submitted by :
Sahil Shakya
B.Tech Biotechnology(7th semester)
4/11/2018

2. AIR SAMPLING
 collection of airborne microorganisms (in the
context of microbiological assessment)
 Air sampling is a critical function of any Quality
Control (QC) laboratory associated with a
Pharmaceutical, Biotech, or healthcare facility.
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3. THE NEED OF AIR SAMPLING
 To protect product integrity, food and beverage
 Prevention of hazardous microbes present in the
atmosphere
 improved quality and increased safety
 reduction of overall production risks and expenses.
 Increase control
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4. MICROBIOLOGICAL AIR SAMPLING
 Two primary methods for microbial air sampling:
 Active monitoring
 Passive monitoring
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5. ACTIVE MONITORING
 microbial air sampler is used to force air into, or onto its
collection medium (e.g., Petri Dish with nutrient agar based
test media) over a specified period of time.
 The collected culture can then be incubated and analyzed
(ie., count bacterial and/or fungal, colony forming units (CFU),
and identify if required)
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6. PASSIVE MONITORING
 settle plates (Petri dishes) are opened and
exposed to the air for specified periods of time to
determine what microbiological particles may be
present in the environment, as they may settle out
of the ambient air, and onto the media surface of
the Petri Dish.
 These plates are then incubated and analyzed.
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8. SEDIMENTATION (PASSIVE)
 primitive method for sampling airborne
microorganisms
 A Petri dish containing a suitable agar is exposed to
the atmosphere and the agar medium will collect
bacteria-laden particles that eventually settle by
gravity
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9. DEFECT
 inefficient for collecting small particles
 In order to counteract this air turbulence effect, the
plate has to be left out longer, which can cause
desiccation
 Agar drying out leads to poor bacterial growth and
reduces the viable count of stress-sensitive
microorganisms
 Settle plates are also impossible to validate
because there is no way to measure the volume of
air sampled
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10. IMPACTORS
 Ex. In a slit-to-agar impactor,
 a known volume of air is drawn by vacuum through a slit
opening and then accelerated and directed toward the
surface of a Petri dish containing agar media.
 The plate rotates on a turntable at a selected rate of
speed and the impacted microorganisms are separated
spatially by the plate’s rotation, providing an analysis
based on time.
 The microorganisms, because of their higher mass,
become impacted on the agar surface, while the rest of
the air mass flows around the plate and exits the air
sampler.
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11. SIEVE SAMPLERS
 stacked sieve samplers can have up to six stages
of perforated plates and agar plates
 each perforated plate is held
above an agar plate with
successive plates having
smaller holes
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12.  At a constant flow, larger particles impact on the
first stage, whereas smaller particles impact on the
last impaction stage
 major advantage of a stacked sieve impactor is that
it can provide data on particle size.
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13. DEFECTS
 nutrient agar can dry out
 plastic dishes may cause electrostatic effect
 inefficiency at collecting smaller particles
 In order to impact smaller particles, the holes need
to be small and the air flow rate should be fast
 however, if the flow rate is too fast, the smaller
microorganisms will be killed due to the shear force
of impact.
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14. CENTRIFUGAL SAMPLERS
 Air is drawn into the sampler by an impeller housed
inside an open shallow drum.
 The air is then accelerated by centrifugal force
toward the inner wall of the drum containing agar
medium onto which airborne particles are impacted.
 ~15 µm and larger particles
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15. CENTRIFUGAL SAMPLER
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16. GELATIN MEMBRANE FILTRATION
 Air is sampled at a programmable flow rate and
passes through the gelatin membrane filter which
captures the microbes
 The filter is 300 µm thick
 absolute retention rate and the only method that
also reliably captures airborne viruses
 air entering the sampler must first pass through the
filter; thereby ensuring microbes are not
reintroduced into the atmosphere
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17. CONCLUSION
 companies can take measures to identify
contamination events earlier for food safety.
 Air monitoring can ensure products are
manufactured to the desired specifications.
 Additionally, new technologies for air monitoring
can help detect contamination events faster and
prevent future instances
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18. THANK YOU
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