788. Continued Presence of Multi-resistant (Non-vaccine) Serotype 15A in Both Invasive and Respiratory Streptococcus pneumoniae Infections in the UK and Ireland
Session: Poster Abstract Session: Vaccines: Pneumococcal
Thursday, October 27, 2016
Room: Poster Hall
Background: Invasive pneumococcal disease declined after adding conjugate vaccine to infant UK immunization schedules - PCV7 in Sept 2006 and PCV13 in April 2010. The BSAC Resistance Surveillance Project tracked concurrent changes in serotypes and antimicrobial resistance (R) and non-susceptibility (NS) in S. pneumoniaefrom bacteremia and community-onset lower respiratory infections (LRTI).

Methods:40 clinical laboratories in the UK and Ireland collected isolates each year. MICs were measured centrally by BSAC agar dilution and interpreted by BSAC/EUCAST breakpoints. Multiple resistance (MULTI-R) was three or more of: PEN-NS (penicillin-NS); TET-R (tetracycline-R); ERY-R (erythromycin-R); FQ-R (ciprofloxacin MIC>8 mg/L).

Results: In the last two years, PCV13 serotypes stabilised at 21-23% in bacteremia and 16-17% in LRTI (table). In the last seasons, PCV13 types were not among the top-3 serotypes in either bacteraemia or LRTI (see table). Serotype 15A increased in LRTI and topped the ranking in LRTI in the last two years, but fluctuated in bacteraemia (table). Serotype 8 ranked top among 2015 blood isolates at 14% (17% in 2014, 15% in 2013) but only 19th and 20thin LRTI at 3% in 2013-14 and 2014-15, respectively. PEN-NS (almost always intermediate), ERY-R, TET-R and MULTI-R all rose in LRTI but not bacteraemia; FQ-R was always rare (<1%). The proportion of MULTI-R isolates was stable at 3% in blood but rose 7% to 12% in LRTI (table). Almost half of these isolates were serotype 15A: 4/8 and 3/7 in blood in 2014 and 2015, respectively; 13/27 and 22/50 in LRTI in 2013-14 and 2014-15, respectively.

Conclusion:Resistance has increased in the last two years in LRTI but not in bacteremia. Non-vaccine serotype 15A contributed substantially to the totality of multiresistance.

S. pneumoniae

UK & Ireland

Number and %

Bacteremia

Lower Respiratory Infection

Jan-Dec’14

Most recent

Jan-Dec’15

Oct’13-Sep’14

Most recent

Oct’14-Sep’15

N of isolates

247

244

376

430

PCV13 types

52 21%

56 23%

63 17%

68 16%

Top 3 serotypes:

type and (%)

8 (17%)

22F (9%)

12F (8%)

8 (14%)

22F (11%)

12F (9%)

15A (9%)

23B (7%)

3 (6%)

15A (11%)

11A (8%)

23A (7%)

serotype 15A

18 7%

9 4%

34 9%

46 11%

PEN-NS

17 7%

14 6%

47 13%

71 17%

ERY-R

21 9%

12 5%

64 17%

92 21%

TET-R

20 8%

13 5%

52 14%

81 19%

MULTI-R

8 3%

7 3%

27 7%

50 12%

Veronique Martin, PhD, Department of Medical Microbiology, North Bristol NHS Trust, Bristol, United Kingdom; British Society for Antimicrobial Chemotherapy, Birmingham, United Kingdom, Shazad Mushtaq, MSc, Public Health England, London, United Kingdom and BSAC Standing Committe on Resistance Surveillance

Disclosures:

V. Martin, None

S. Mushtaq, None

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