Activeforever CIDEX Plus Solution - Manual (Page 4)

that a 0.5% OPA was rapidly mycobactericidal under
both “clean” and “dirty” conditions.
19 In particular,
the solution was active against glutaraldehyde-resistant
strains of mycobacteria.
19 Another study using a
quantitative suspension protocol found that OPA is
effective as a tuberculocidal disinfectant: at MEC levels,
OPA achieved a 6-log
10
reduction of Mycobacterium
bovis in nearly one-sixth the time required with
glutaraldehyde (5.5 minutes versus 32 minutes).
20
In a study of the mechanisms of the mycobacterial
action of ortho-phthalaldehyde, glutaraldehyde, and
chlorhexidine diacetate, Fraud and colleagues concluded
that, “The rapid micobactericidal effect of OPA probably
arises from its more efficient penetration across
biological membranes.”
21
Antibiotic-Resistant Bacteria
Drug-resistant bacterial infection is a widespread health
concern, and some controversy exists as to whether
resistance to antibiotics is somehow related to resistance
to disinfectants. Two common drug-resistant organisms,
MRSA (ATCC
® #33592) and VRE (ATCC ® #51299), have
been tested with CIDEX ® OPA Solution.
As in the efficacy tests with mycobacteria, these assays
evaluated reused CIDEX
® OPA Solution in conformance
with EPA specifications. Stainless steel carriers coated
with bacteria were submerged in reused solution diluted
to 0.3% at 20°C. After a 10-minute exposure, carriers
were placed into individual containers of culture
medium containing an agent that neutralizes
ortho-phthalaldehyde. Each strain was
used in triplicate tests involving 10 carriers
each. No organisms survived exposure to
the dilute solution, illustrating that the
antibiotic-resistant strains of S. aureus
and E. faecalis demonstrate no increased
resistance to dilute CIDEX OPA Solution.
17
Clostridium Difficile
Clostridium difficile, a spore-forming,
gram-positive anaerobic bacillus, is the
leading cause of antibiotic-associated
diarrhea in hospitalized patients. The serious
health effects of C. difficile include diarrhea,
colitis, blood poisoning, and even death.
This, combined with an increasing prevalence
and incidence, make C. difficile a significant
healthcare issue.
22
A recent study, results of which were
presented at the APIC 2008 Annual
Conference, evaluated the biocidal activity
of an ortho-phthalaldehyde solution
(prepared from CIDEX
® OPA Solution)
against C. difficile. Results showed that
OPA is efficacious against the vegetative
form and achieves a significant reduction of the spore
form of
C. difficile. (See Figure 1) In particular, there
were no surviving C. difficile vegetative cells observed
after a 2-minute exposure in 0.3% OPA at 20° C. With
the spore form of C. difficile, a 2.4 log
10
reduction was
demonstrated with 0.3% OPA and at least 4.9 log
10
reduction with 0.5% OPA after a five-minute exposure. 23
Viruses
Hepatitis B and C viruses (HBV and HCV)—the most
prevalent blood-borne viruses
24 —are parenterally
transmitted infectious agents that are a major cause
of acute hepatitis and chronic liver disease, including
cirrhosis and cancer. Disinfection of HBV is assayed
with an in vitro test using duck hepatitis B virus as a
surrogate for HBV.
To test the efficacy of CIDEX ® OPA Solution against
the HBV surrogate, a suspension of duck hepatitis
B virus was dried on a Petri dish, then exposed to
0.3% ortho-phthalaldehyde for 5 minutes at 20°C.
The bottom of the dish was scraped, and the resulting
suspension was passed though a filtration column to
remove the CIDEX OPA Solution. In the immuno-
fluorescence assay, the number of viable virus
particles was reduced by more than 4 logs after
exposure to 0.3% CIDEX OPA Solution.
15
Similar tests were done with bovine viral diarrhea virus,
a surrogate for HCV. For these tests, virus suspensions
also contained 5% horse serum as organic soil. This
0
1
2
3
4
5
6
0.3% OPA vs.
C. difficile
vegetative cells
at 20°C
0.3% OPA vs.
C. difficile
spores
at 20°C
0.3% OPA vs.
C. difficile
spores
at 25°C
0.5% OPA vs.
C. difficile
spores
at 25°C
Log of Surv
ivo
rs
0 min. 2 min. 5 min.
10 min. 12 min. 15 min.
Test Conditions
Figure 1. OPA Solution Versus Clostridium Difficile at Various
Study Conditions.
4