1. Characterization of B-lactam resistance mechanisms among UTI isolates collected from women attending primary care across Europe- RGNOSIS
P-0730
26th ECCMID
Apr 9th – Apr 12th 2016
Amsterdam, Holland
JM Tyrrell1, Abokliash A1, Richards J3, Butler C2, Wootton M3, Walsh TR1, Carvalho MJ1.
 1Department of Medical Microbiology & Infectious Diseases, Cardiff University, Heath Park, Cardiff, Wales, UK. 2Nuffield Department of Primary Care Health Services, University of Oxford, Oxford, UK. 3Public Health Wales Microbiology, Cardiff, University Hospital of Wales, Heath Park, Cardiff, Wales, UK.
Introduction
Results
RGNOSIS (Resistance in Gram Negative Organisms- Studying Intervention Strategies) is an European collaborative study involving clinical studies supported by highly innovative microbiological analysis to determine the efficacy of cutting edge interventions to reduce carriage, infection and dissemination of multi-drug resistant Gram-negative organisms (MDR-GNB).
Herein we describe the antibiotic susceptibility profiling of predominant UTI specimens collected from primary care centres in the UK, Spain & Netherlands These strains were collected during the observational & randomised clinical trial (RCT) phases of POETIC (Point Of CarE Testing for Urinary Tract Infection in Primary care- RGNOSIS WP2). Subsequent investigation into the molecular basis of β-lactam resistance was also undertaken.
PFGE Profile
Origin
Species ID
Sequence Type (ST)
AR Phenotype
AR Gene I
Spain
E. coli
ST69
AmpC
blaCIT(CMY-2)
ST92
MBL + AmpC
NGI UK
ST131
MBL + AmpC II
Netherlands
ESBL + AmpC
blaCTX-M-15
III
ESBL IV V
blaCTX-M-14 VI
VII
VIII
blaTEM-15 IX
ST93 X
ST372
CTX-M Grp1 XI
ST73
XII
A. johnsonii -
blaDHA-22
XIII
A. pittii
XIV
H. alvei
Methods
UTI Specimens collected (n=556)
Species ID by MALDI-Tof
Antibiotic susceptibility testing (CLSI/EUCAST V5.0 guidelines)
Figure 1: Resistance & Susceptibility Rates (%) vs extensive antibiotic panel.
Further genetic characterisation:
Gene sequencing
XbaI PFGE analysis
MLST
AR Genetic confirmation
by PCR:
blaCTX-M, blaTEM, blaSHV
blaMOX, -CIT, -DHA, -ACC, -EBC,-FOX
blaNDM, -VIM, -SPM
AR Phenotypic synergy testing:
ESBL
AmpC
MBL
Table 1: Genetic characterisation of ESBL/AmpC/MBL-producing organisms.
AR- Antibitiotic Resistance. NGI- No gene identified.
expressing an ESBL / AmpC / MBL phenotype. These included E. coli (n=13), A. johnsonii (n=1), A. pittii (n=1) and H. alvei (n=1) from across our three collection sites (Spain, Netherlands, UK) (Table 1).
Of 9 E. coli expressing ESBL phenotypes, blaCTX-M-14 (n=4) and blaCTX-M-15 (n=3) were the most prevalent genes identified. The genes blaCIT(CMY-2) and blaDHA-22were correlated with an AmpC phenotype in E. coli and A. johnsonii respectively. An MBL phenotype was identified in 3 isolates, but no resistance gene was identified.
E. coli isolates were typed by both XbaI PFGE analysis and MLST. Three E. coli showed homologous PFGE profiles (Profile I , Table 1), but were characterised as 3 separate STs (ST69, 92 and 131). They were isolates from Spain and UK respectively, and showed similar antibiogram profiles. The high risk ExPEC ST131 was the predominant ST identified; blaCTX-m-14, and not blaCTX-M-15, was the most prevalent blaESBL in these strains.
Results
556 GNB isolates were collected, from which Escherichia coli (84%), Proteus mirabilis (3.4%) and Klebsiella pneumoniae (3.2%) were the most prevalent species, with 0.9% Acinetobacter spp., & Pseudomonas spp., also collected.
Rates of antibiotic susceptibility/resistance can be seen in Figure 1. Rates of resistance were in the main <5%; the exceptions being amoxicillin (44.7%), Co-amoxiclav (11.2%), trimethoprim (20.5%) and fosfomycin (5.8%).
Antibiotic-inhibitor synergy testing identified 16 separate isolates
Conclusions & Highlights
Low rates of antibiotic resistance were recorded among UTI-implicated GNB across Europe.
Significant resistance to antibiotics widely used in the treatment of community acquired infections was reported. Trimethoprim (20.5% R) rates were lower than previously reported (~30% R).
E. coli ST131 carrying blaCTX-M-14 was the predominant causative organism of antibiotic resistant UTIs.
Larger samples are needed to further characterise the evolving epidemiology of antibiotic resistant UTIs
Contact-