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overview of bacterial populations. The aim of this study was to
determine if cadexomer iodine as a mono-therapy could reduce
biofilm phenotype bacteria colonizing diabetic foot ulcers (DFUs) in-
vivo
Results:
Staphylococcus aureus
,
Staphylococcus epidermidis
,
Prevotella
melaninogenica, Elizabethkingia meningoseptica, Propionibacterium
acnes
and
Pseudomonas stutzeri
were the most abundant bacterial
species present across the samples before and after treatment. We
observed a significant decrease in the diversity of and changes in the
community composition after treatment with an increase in bacterial
abundance. The presence of biofilm was determined via scanning
electron microscope. We found that Iodosorb reduced but did not
remove biofilms from 50% of the samples, whereas 36% revealed no
changes and 14% started to produce biofilm. Log reductions of biofilm
cells indicated that in 9 of 15 patients, a reduction of between 1 and
3 log
10
was possible.
Discussion and/or Conclusion(s):
Given the inherent tolerance of
biofilms to many forms of antimicrobials, cadexomer Iodosorb
demonstrated the ability to decrease bacterial diversity, load and
biofilm formation. The effectiveness of this topical antimicrobial
maybe increased further if used as an adjunct therapy in a biofilm
based woundcare model. Additional analysis of wound characteristics
and any shifts in community diversity are required to clarify why some
wounds bacterial loads increase with the apparent use of cadexomer
iodine.
ID: 4808
Routinewashing of patients with octenisan
–
is it theway forward?
Katie Hardy
1
, Gill Abbott
2
, Jane Codd
2
, Katie Sunnocks
3
, Hannah Gil
3
,
Sahida Shabir
2
, Carolyn Lewis
2
, Peter Hawkey
1
, Mark Webber
3
.
1
Public
Health England,
2
Heart of England NHS Foundation Trust,
3
University of
Birmingham
Background:
Antiseptic body washes are used as part of the
decolonisation treatment for patients known to be colonised with
MRSA, but there has also been a move to use antiseptic body washes
for routine washing of all patients for the duration of their hospital
stay.
Aim(s)/Objective(s):
In 2014, octenisan was introduced Trust wide
for routine washing for all patients. This study aimed to review the
introduction assessing the use, acceptability and susceptibility.
Method(s):
Usage data, in the form of number of bottles of octenisan
was ascertained for March 2014 to April 2015. Two questionnaires
were developed to determine both staff and patient opinion regarding
the information received about the antiseptic, the usage and accep-
tability. MIC and MBCs to octenisan were established for a panel of 77
MRSA isolates pre and post octenisan introduction.
Results:
The usage of octenisan varied by clinical area. A total of 237
staff and 99 patient questionnaires were completed and demonstrated
a need for improved communication regarding both the availability
and the correct duration for application, with only 3% knowing correct
duration. Both patients and staff stated that they would be happy to
continue using octenisan (98%) with no skin irritation being reported.
Eleven isolates had anMBC >1 μg/mL, with the number increasing post
introduction 9.8% (5/51) versus 23.1% (6/26).
Discussion and/or Conclusion(s):
Octenisan was widely accepted by
both staff and patients, but there is a need for improved communi-
cation to ensure the product is being used effectively, especially in
light of evidence of an increase in decreased susceptibility.
ID: 4813
Despite widespread use, fluoroquinolone resistance in
Mycobacterium tuberculosis
is unusual in Singapore
Timothy Barkham, Wen Ying Tang, Cynthia Chee, Sonny Wang.
Tan
Tock Seng Hospital
Background:
Fluoroquinolones (FQ) are important second line
antibiotics for tuberculosis (TB) but are only tested if an isolate of
Mycobacterium tuberculosis
(MTBC) is resistant to first line drugs. Data
on FQ resistance rates are scarce as resistance to first line drugs had
been a trickle in Singapore, with only four rifampicin resistant and
six multi drug resistant cases in 2011. The annual incidence of TB was
40/100,000, equivalent to about 2000 TB cases/year. Concern was
raised that thewidespread use of FQs, often for urinary and respiratory
tract conditions, may be selecting for FQ resistant MTB and that we
aren
’
t aware of it because we don
’
t test enough isolates. Note that FQ
resistance is 50
–
60% amongst hospital strains of Enterobacteriaceae.
The concern was that when rifampicin resistance does become more
common, we may then unearth a hidden problem of FQ resistance that
may precipitate the emergence of
‘
XDR
’
TB.
Aim(s)/Objective(s):
To measure the prevalence of fluoroquinolone
resistance in MTBC.
Method(s):
Clinical samples from 364 patients, submitted between
2014 and 2016, that were smear and subsequently TB PCR positive
were tested for quinolone resistance by amplification and sequencing
of the quinolone resistance determining region.
Results:
A single mutation associated with quinolone resistance,
either A90V, D94G or S91P, was found in three samples.
Discussion and/or Conclusion(s):
This FQ resistance rate of <1%
is lower than the 2.5% rate reported in a study from the USA in 2009
and is lower than the rate of 3.5% seen in local MTBC with resistance to
a first line drug.
ID: 4826
A comparison of
pncA
gene sequencing with Mycobacterial Growth
Indicator Tube (MGIT) for detecting pyrazinamide resistance in
Mycobacterium tuberculosis
Rachel Halkerston
1
, Amie-Louise Seagar
2
, Pauline Claxton
2
,
Ian Laurenson
2
.
1
The University of Edinburgh, Biomedical Teaching
Organisation,
2
Scottish Mycobacteria Reference Laboratory
Background:
Pyrazinamide (PZA) is a key drug for treating tubercu-
losis, but diagnosing PZA-resistance is technically challenging.
Mycobacterial Growth Indicator Tube (MGIT) 960 resistance deter-
mination may overestimate phenotypic resistance compared with the
now obsolete Bactec 460. Mutations in the
pncA
gene, which encodes
the enzyme pyrazinamidase, cause the majority of PZA-resistance.
Aim(s)/Objective(s):
To determine whether
pncA
sequencing predicts
PZA-resistance by comparing mutation presence to the phenotypic
MGIT 960 result amongst isolates also resistant to isoniazid and/or
rifampicin.
Method(s):
We examined 48
M. tuberculosis
isolates referred to
the Scottish Mycobacteria Reference Laboratory between 2006 and
2015. The MGIT 960 phenotypic PZA-resistance and
pncA
gene
sequencing was carried out on all isolates. All mutations were
evaluated by comparison to the tuberculosis mutation databases
TBDReaMDB and MUB-II-TB-DB, with a systematic review of PUBMED
literature published March 2013 to March 2016 inclusive.
Results:
We observed MGIT 960 PZA-resistance and a
pncA
mutation
in 21 of 48 isolates.
pncA
mutations were detected in 3 MGIT 960 PZA-
susceptible isolates. The sensitivity of
pncA
sequencing for detecting
resistance was 100% (95% Confidence Interval (CI): 81.0% to 100%) and
specificity 88.9% (95% CI: 69.7% to 97.1%). We identified 3 mutations
not previously reported in the literature.
Discussion and/or Conclusion(s):
Amongst these isolates
pncA
sequencing is a good predictor for PZA-resistance in if used in con-
junction with the MGIT 960. Three new mutations were identified.
Future research should include evaluation of pyrazinamidase activity,
rpsA
and
panD
genes.
ID: 4827
Epidemiology and outcomes of carbapenem-resistant Gram-
negative infections; a single-center experience from Saudi Arabia
Lina N. Albalawi, Kareemah Alshurtan, Sarah Alajmi,
Mohamed Bohlega, Noha Mukhtar, Sahar Althawadi,
Abdulrahman Alrajhi, Mohamed Shoukri, Ali S. Omrani.
King Faisal
Specialist Hospital and Research Centre
Abstracts of FIS/HIS 2016
–
Poster Presentations / Journal of Hospital Infection 94S1 (2016) S24
–
S134
S28