Molecular characterization of OXA-48 carbapenemase-producing Klebsiella pneumoniae strains after a carbapenem resistance increase in Catalonia.

INTRODUCTION: To characterize OXA-48 carbapenemase-producing Klebsiella pneumoniae strains isolated after an increase in carbapenem resistance in Catalonia. METHODOLOGY: K. pneumoniae identification, antimicrobial susceptibility studies, the Modified Hodge Test method, amplification of antimicrobial resistance genes (against ß-lactamases, quinolones and aminoglycosides), molecular typing (by PFGE and MLST), conjugation assays, plasmid characterization (PBRT-PCR and Southern blot), a description of mobile genetic elements and statistical analysis were done. RESULTS: OXA-48 was the only carbapenemase detected, with a prevalence of 1.9%. The blaOXA-48 gene was located in an IncL conjugative plasmid of 62kb and integrated into the transposons Tn1999.2 (91.7%) or Tn1999.1. Five PFGE profiles (A to E) were found, which exactly matched the MLST: ST101, ST17, ST1233, ST14 and ST405, respectively. ST1233 is described here for the first time. K. pneumoniae OXA-48-producing strains were also CTX-M-15 carriers, some producing OXA-1 and TEM-1 penicillinases. The acquired qnrB66 and qnrB1 and aac(3')-IIa, aac(6')-Ib genes were also identified. CONCLUSION: The K. pneumoniae ST405 clone has played an important role in the growing prevalence of OXA-48 in Catalonia. All clones described preserved the blaOXA-48 genetic environment and mobile genetic elements (Tn1999). Notably, the three strains with minor sequence types in this study are not multiresistant strains. These strains are expanding in elderly patients (average age of 76 years) with serious underlying diseases, mainly women (61.2%).

Serotypes and Clonal Diversity of Streptococcus pneumoniae Causing Invasive Disease in the Era of PCV13 in Catalonia, Spain.

The aim of this study was to study the serotypes and clonal diversity of pneumococci causing invasive pneumococcal disease in Catalonia, Spain, in the era of 13-valent pneumococcal conjugate vaccine (PCV13). In our region, this vaccine is only available in the private market and it is estimated a PCV13 vaccine coverage around 55% in children. A total of 1551 pneumococcal invasive isolates received between 2010 and 2013 in the Molecular Microbiology Department at Hospital Sant Joan de Déu, Barcelona, were included. Fifty-two serotypes and 249 clonal types-defined by MLST-were identified. The most common serotypes were serotype 1 (n = 182; 11.7%), 3 (n = 145; 9.3%), 19A (n = 137; 8.8%) and 7F (n = 122; 7.9%). Serotype 14 was the third most frequent serotype in children < 2 years (15 of 159 isolates). PCV7 serotypes maintained their proportion along the period of study, 16.6% in 2010 to 13.4% in 2013, whereas there was a significant proportional decrease in PCV13 serotypes, 65.3% in 2010 to 48.9% in 2013 (p<0.01). This decrease was mainly attributable to serotypes 19A and 7F. Serotype 12F achieved the third position in 2013 (n = 22, 6.4%). The most frequent clonal types found were ST306 (n = 154, 9.9%), ST191 (n = 111, 7.2%), ST989 (n = 85, 5.5%) and ST180 (n = 80, 5.2%). Despite their decrease, PCV13 serotypes continue to be a major cause of disease in Spain. These results emphasize the need for complete PCV13 vaccination.

Serotypes and clones causing invasive pneumococcal disease before the use of new conjugate vaccines in Catalonia, Spain.

OBJECTIVES: The objective of this study was to learn the serotype distribution and clonal composition of pneumococci causing invasive pneumococcal disease (IPD) in children and adults in Spain before the introduction of new 10-valent (PCV10) and 13-valent (PCV13) conjugate vaccines. METHODS: This is a 1-year prospective study including all patients with culture-proved IPD admitted to 30 medical centers in Catalonia, Spain, during the year 2009. RESULTS: A total of 614 episodes of IPD occurred in 612 patients. The rates of IPD were highest in children aged <24 months and adults >64 years (64.5 and 44.7 per 100,000 population). The burden of disease was mainly due to pneumonia in all age ranges. 609 of 614 strains were serotyped and 47 different serotypes were found. Among the 609 IPD cases with known serotype, 12.2% were caused by PCV7 serotypes, 51% by PCV10 serotypes, and 71.7% by PCV13 serotypes. 608 of 614 isolates were characterized by MLST. The main clonal types detected were ST306, CC191 and CC230. CONCLUSIONS: PCV13 conjugate vaccine offers good coverage against IPD in Catalonia, Spain. However, the high genetic diversity of pneumococci highlights the importance of molecular surveillance systems for monitoring IPD during the vaccination period. SUMMARY: This study shows that 13-valent conjugate vaccine offers good coverage against invasive pneumococcal disease in children and adults in Spain. However, the high genetic diversity of pneumococci highlights the importance of molecular surveillance systems for monitoring IPD during the vaccination period.