Common STs Research Articles

High Prevalence of Escherichia coli-Producing CTX-M-15 Extended-Spectrum Beta-Lactamases in Poultry and Human Clinical Isolates in Romania.

Use of antibiotics in food animals may contribute to development and spread of resistant organisms, particularly so in some countries. The aim of this study was two-fold; first, to establish the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in chicken production in a region within Romania. Second, to study the relatedness of ESBL-producing E. coli isolates recovered from broilers, abattoir workers where the chickens were slaughtered and from the human clinical specimens from two regional hospitals. The results indicated a very high (69%) rate of carriage of ESBL and AmpC-producing E. coli in chickens with 36% CTX-M producers. Sequencing showed that chickens in Romania have the highest worldwide prevalence (53%) of blaCTX-M-15 reported in poultry E. coli isolates. The majority (53%) of the extended-spectrum cephalosporin-resistant E. coli carried plasmid-mediated blaampC genes, mostly blaCMY-2 type, one of the highest prevalences reported in Europe. The predominant CTX-M type found in the human clinical E. coli isolates was blaCTX-M-15 and most isolates coharbored blaOXA-1, blaTEM, and aac(6')-ib-cr. The majority (60%) of the human clinical isolates belonged to the pandemic virulent clone B2-ST131. The clonal relationship between broiler and the human CTX-M-producing E. coli isolates was assessed by macrorestriction pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), which indicated strain diversity with no common STs found between human and poultry isolates. Moreover, IncI1 was the most prevalent replicon found in broiler ESBL-producing E. coli isolates and also in transconjugants, indicating that plasmids and not clonal spread may play a role in the transfer of blaCTX-M genes. This study identifies a high prevalence of ESBL-producing E. coli from broiler chickens in Romania with a high occurrence incidence of blaCTX-M-15, which reflects the main ESBL type found in human E. coli infections in this country.

Antimicrobial susceptibilities and distribution of sequence types of Neisseria gonorrhoeae isolates in Canada: 2010

The monitoring of antimicrobial susceptibilities in Neisseria gonorrhoeae isolates and characterization of N. gonorrhoeae multiantigen sequence types (NG-MAST, ST) provide important surveillance data as resistance rates continue to rise. A total of 2970 N. gonorrhoeae isolates were collected by Canadian provincial public health laboratories in 2010, and 1233 were submitted to the National Microbiology Laboratory for testing. The NG-MAST and minimum inhibitory concentration (MIC) by agar dilution were determined for each isolate. Of the 2970 isolates, 25.1% were resistant to penicillin, 34.6% resistant to tetracycline, 31.5% resistant to erythromycin, 35.9% resistant to ciprofloxacin, and 1.2% resistant to azithromycin. Decreased susceptibility to cefixime (MIC ≥ 0.25 mg/L) and ceftriaxone (MIC ≥ 0.125 mg/L) was identified in 3.2% and 7.3% of the isolates, respectively. The most common STs found in Canada were ST1407 (13.3%), ST3150 (11.3%), and ST3158 (9.0%), with 249 different STs identified among the isolates. Within the ST1407 group, 19.5% and 43.3% isolates have decreased susceptibility to cefixime and ceftriaxone, respectively. ST1407, the most prevalent NG-MAST in Canada in 2010, has been associated with high-level ceftriaxone MICs and with cefixime treatment failure cases worldwide. Identification and monitoring of STs and corresponding antimicrobial resistance profiles may be useful in surveillance programs and be used to inform public health actions.

P3.282 Multi-Antigen Sequence Types (NG-MAST) and Antimicrobial Susceptibilities on Neisseria Gonorrhoeae Isolated in Canada, 2010–2011

BackgroundNeisseria gonorrhoeae have acquired resistance to many antibiotics and have developed decreasing susceptibilities to 3rd generation cephalosporins.MethodNG-MAST sequence types and minimum inhibitory concentration (MICs) by agar dilution were determined for...

P3.270 Antimicrobial Susceptibility and Molecular Characterization of Neisseria Gonorrhoeae Strains from Slovenia 2008–2012

ObjectivesAntimicrobial resistance in Neisseria gonorrhoeae is a major public health problem worldwide. Slovenia is among the countries with highest prevalence of decreased susceptibility and resistance to extended-spectrum cephalosporins (ESCs) in...

Genetic diversity and molecular typing of Listeria monocytogenes in China

BackgroundListeria monocytogenes can cause invasive diseases in humans and farm animals and is frequently isolated from dairy products and poultry. Listeriosis is uncommon in China but L. monocytogenes has been isolated from foods and food processing environments in China. However little is known of genetic diversity of Chinese L. monocytogenes isolates and their relationships with global isolates.ResultsTwo hundred and twelve isolates of L. monocytogenes from food sources from 12 provinces/cities in China were analysed by serotyping, Pulsed Field Gel Electrophoresis (PFGE) and Multi-locus Sequence Typing (MLST). The predominant serotypes are 1/2a, 1/2b and 1/2c accounting for 90.1% of the isolates. PFGE divided the isolates into 61 pulse types (PTs). Twenty nine PTs were represented by more than one isolates with PT GX6A16.0004 containing the most number of isolates. MLST differentiated the isolates into 36 STs, among which 15 were novel. The 3 most common STs were ST9 (29.1%), ST8 (10.7%) and ST87 (9.2%), accounting for 49.0% of the isolates.ConclusionsSTs prevalent in other parts of the world are also prevalent in China including 7 STs (ST1-ST3, ST5, ST6, ST8, ST9) which caused maternal fetal infections or outbreaks, suggesting that these STs potentially can also cause severe human infections or outbreaks in China. Surveillance of these STs will provide important information for prevention of listeriosis. This study also enhances our understanding of genetic diversity of L. monocytogenes in China.

Geriatric high-grade soft tissue sarcoma (G-HG STS): An analysis of 116 patients (pts) evaluating prognostic factors and clinical outcomes stratified by histology.

10051 Background: STS in geriatric pts is not well studied. We evaluated prognostic factors and clinical outcomes in elderly pts with HG STS. Methods: Single centre retrospective study. G-HG STS pts defined as age > 65 yrs seen in our centre from 2002 - 2011 with complete medical records were identified. Charlson age-comorbidity score was assessed for each pt. Results: 116 pts from 4 most common HG STS histo-types representing 69% of pts in the geriatric STS cohort were analysed; leiomyosarcoma (LMS, 14%), non well-differentiated liposarcoma (nWD-LPS, 9%), angiosarcoma (AS, 30%), and undifferentiated pleomorphic sarcoma (UPS, 47%). Median age was 72 yrs, 81% presented with localised disease; of 78% of these localised pts who had curative surgery, 49% received adjuvant therapy, of whom 92% had radiotherapy (RT) only. AS arises more commonly from the head/neck region (p<0.001) and fewer receive curative surgery (p=0.006). In 43 pts who had metastases either at diagnosis or relapse, 33% received first-line palliative chemotherapy with a response rate of 27% in evaluable pts. At a median follow-up of 15.8 mths, overall survival (OS) for the entire cohort was 25.1 mths, 30.5 vs 3.9 mths in pts presenting with localised vs metastatic disease respectively (p<0.0001). In pts who had curative surgery for localised disease, overall relapse-free survival (RFS) was 17.7mths; 26.8 mths vs 16.0 mths vs 7.3 mths vs 12.5 mths in LMS, nWD-LPS, AS and UPS respectively. In univariate analysis, adjuvant RT, non-head/neck primary and sarcoma subtype were associated with improved RFS. In multivariate analysis, adjuvant RT (p<0.001), sarcoma subtypes AS (p=0.011) and UPS (0.012) vs LMS remained significant. In pts with metastatic HG STS either at diagnosis or relapse, overall median OS was 5.9 mths; 5.9 mths (LMS), 30.5 mths (nWD-LPS), 6.4 mths (AS) and 4.3 mths (UPS). In univariate analysis, presence of bone metastases was significantly associated with inferior OS (p=0.0029). Charlson score did not correlate with RFS or OS. Conclusions: Prognosis of G-HG STS appears poor particularly in AS and UPS. Adjuvant RT improves outcomes in this group of pts and should not be omitted based on age alone.

Distribution of Monoclonal Antibody Subgroups and Sequence-Based Types among Legionella pneumophila Serogroup 1 Isolates Derived from Cooling Tower Water, Bathwater, and Soil in Japan

Legionella pneumophila serogroup (SG) 1 is the most frequent cause of legionellosis. This study analyzed environmental isolates of L. pneumophila SG 1 in Japan using monoclonal antibody (MAb) typing and sequence-based typing (SBT). Samples were analyzed from bathwater (BW; n = 50), cooling tower water (CT; n = 50), and soil (SO; n = 35). The distribution of MAb types varied by source, with the most prevalent types being Bellingham (42%), Oxford (72%), and OLDA (51%) in BW, CT, and SO, respectively. The ratios of MAb 3/1 positive isolates were 26, 2, and 14% from BW, CT, and SO, respectively. The environmental isolates from BW, CT, and SO were divided into 34 sequence types (STs; index of discrimination [IOD] = 0.973), 8 STs (IOD = 0.448), and 11 STs (IOD = 0.879), respectively. Genetic variation among CT isolates was smaller than seen in BW and SO. ST1 accounted for 74% of the CT isolates. The only common STs between (i) BW and CT, (ii) BW and SO, and (iii) CT and SO were ST1, ST129, and ST48, respectively, suggesting that each environment constitutes an independent habitat.