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accuracy of newer technologies such as MALDI-TOF MS. In this

retrospective study we compare MALDI-TOF MS with biochemical

identification.

Aim(s)/Objective(s):

To assess the accuracy of MALDI-TOF MS for the

identification of

Neisseria gonorrhoeae

in comparison with biochem-

ical identification (Biomerieux API NH).

Method(s):

Laboratory records of all Genitourinary Medicine culture

samples between January 2012 and October 2014 were reviewed

retrospectively. All isolates with both an API NH and MALDI-TOF MS

identification recorded were included; a subset analysis examined the

reasons for requiring repeat MALDI-TOF MS analysis.

Results:

1190 isolates were eligible for inclusion, with 1082 biochem-

ically identified as

Neisseria gonorrhoeae

. MALDI-TOF MS identified

984 (91%) of these correctly after one analysis, rising to 1081 (99.9%)

after two analyses. Failure to generate an acceptable identification

score was the reason for repeat analysis in 76% of cases; the remaining

24% of isolates were either initially identified as other

Neisseriae

or as

genetically dissimilar contaminating organisms incorrectly sampled

from culture media.

Discussion and/or Conclusion(s):

MALDI-TOF MS is an accurate

and reliable method of identifying

Neisseria gonorrhoeae

. Laboratories

with access to this technology could consider its use as a single

method of identification in routine cases.

ID: 4743

Evaluation of the feasibility of using C-reactive protein (CRP) to

optimise prescribing for lower respiratory tract infections in

primary care settings

Jacqueline Sneddon

1

, William Malcolm

2

, Gail Haddock

3

,

Simon Hurding

4

, Alastair Leanord

5

, Dilip Nathwani

6

.

1

Healthcare

Improvement Scotland,

2

NHS National Services Scotland,

3

NHS Highland,

4

NHS Lothian,

5

The Scottish Government,

6

NHS Tayside

Background:

The Scottish Antimicrobial Prescribing Group has

developed several initiatives to promote reduction of unnecessary

antibiotic use for respiratory tract infections in primary care.

Aim(s)/Objective(s):

This study was developed to evaluate the feasi-

bility of using CRP testing, as recommended by NICE, to support

clinical decision making in lower respiratory tract infections (LRTI) in

GP practices in Scotland.

Method(s):

A study steering group was established to provide advice

on methodology and governance issues. Ten GP Practices were recrui-

ted across four health board areas to take part in the study. Following

training, practices used the CRP testing on patients presenting

with suspected LRTI for at least 4 weeks during the period

November 2015

February 2016. Data collected during consultations

and GP feedback were analysed to determine the practical aspects of

how the test was used and its perceived impact on GP decision making

and prescribing of antibiotics.

Results:

Data suggests that CRP testing can be accommodated with

the current appointments system, by either the GP running the test

during the consultation or a practice nurse performing the test in a

nearby treatment room. The test appeared to reduce the number of

immediate prescriptions, increase use of delayed prescriptions and

provided reassurance for both prescribers and patients when no

antibiotic was used. Study results will be used to inform future strategy

for point of care testing for community infections.

Discussion and/or Conclusion(s):

CRP testing is practical in the

Scottish primary care context and offers an additional tool to

support reduction of unnecessary use of antibiotics for respiratory

infections.

ID: 4757

Evaluation of Xpert Influenza assay; easy to use but moderate

sensitivity and no subtype data

Timothy Barkham

1

, Janice Leong

1

, Masafumi Inoue

2

.

1

Tan Tock Seng

Hospital,

2

Experimental Therapeutics Centre, Agency for Science,

Technology and Research

Background:

Testing for Influenza with nucleic acid tests (NATs) is a

daily activity. The desire to know subtypes, originally driven by the

threat of H5N1, led to the introduction of a single tube NAT that

delivers results for Influenza A, B and subtypes H1N1 and H3N2. The

weakness of the system is that samples are run in batches. In contrast,

an apparent strength of the Xpert flu assay is that it is run on a random

access instrument, allowing individual samples to be processed

without waiting for a batch.

Aim(s)/Objective(s):

To compare the Xpert assay with the assay in

routine use.

Method(s):

146 clinically requested samples were run on the in use

abTEST Flu 4 QPCR I kit and the Xpert Flu/RSV XC kit in June 2015.

Analysis assumed the in use assay to be correct as accumulated quality

assurance data showed excellent performance.

Results:

The Xpert system detected 31/35 H3N2, 34/35 H1N1, 30/35

Influenza B and 1/1 Influenza A without subtype: a total of 96/106

(90%). Five of the missed cases were due to a

failed

run. The Xpert

system did not detect influenza in any of the 40 samples reported as

not detected

by the in use assay.

Discussion and/or Conclusion(s):

Failed runs, linked with micro-

fluidics, are a significant weakness of the Xpert system. Detection

sensitivity is 10% inferior to our current system and the Xpert does not

deliver subtypes, nor can it be updated with amended primers/probes

at short notice. This can be crucial when dealing with outbreaks of new

subtypes requiring different management.

ID: 4858

Direct Lancefield grouping for the rapid identification of

streptococci in blood cultures

Melissa Baxter

1

, Aiden Plant

1

, Marina Morgan

1

.

1

Royal Devon and Exeter

NHS Foundation Trust

Background:

Standard laboratory identification of the Lancefield

group of Streptococci is by latex agglutination for the carbohydrate

antigen primarily from a colony following incubation and growth of

the organism. We sought to determine the reliability of undertak-

ing Streptococcal grouping directly from positive blood cultures,

proposing that the rapid identification may expedite appropriate

antimicrobial therapy, infection control precautions and public health

notification.

Methods:

Positive blood cultures (BacTalert 3D) with Streptococci

identified on Gram

s stain were prospectively subjected to direct

Lancefield A, B, C and G grouping (Prolab diagnostics) from December

2015 to June 2016. Comparison was made with final identification on

completion of culture, either by repeat Lancefield grouping or MALDI-

TOF analysis.

Results:

Of 53 blood cultures positive for

β

-haemolytic streptococci, 32

were subject to direct Lancefield grouping. 27 agglutinated with a

single group, whilst five remained agglutination negative. All of the 27

yielded the same organismon final culture (

p

= 0.02). The five negative

agglutinations cultured Group A streptococcus on four occasions and

Group G streptococcus on one.

Discussion:

We report 84.4% sensitivity in identification of Strepto-

coccal bacteraemia with direct Lancefield grouping. Importantly there

were no false positives. We propose direct grouping is a useful adjunct

in the interpretation of positive blood cultures pending confirmatory

testing. The utility of this with regard to clinical impact is yet to be

evaluated.

ID: 4866

Finding the needle in the haystack: Screening for CPOs at a large

London Teaching Hospital using Rosco Confirm Kits

Gemma Vanstone

1

, Damien Mack

2

, Indran Balakrishnan

3

.

1

HSL

Analytics,

2

The Royal Free London NHS Foundation Trust,

3

The Royal Free

NHS Foundation Trust

Background:

Several methods for the detection of carbapenemase

producing organisms (CPOs) are now available, with different

Abstracts of FIS/HIS 2016

Poster Presentations / Journal of Hospital Infection 94S1 (2016) S24

S134

S75