Emerging non-13-valent pneumococcal conjugate vaccine (PCV13) serotypes causing adult invasive pneumococcal disease in the late-PCV13 period in Spain.

OBJECTIVE: An early reduction of adult invasive pneumococcal disease (IPD) was observed after the 13-valent pneumococcal conjugate vaccine (PCV13) introduction for children in Spain. We analysed the epidemiology of adult IPD in the late-PCV13 period. METHODS: This was a prospective multicentre study of adult IPD involving six hospitals. Strains were serotyped, genotyped and studied for antimicrobial susceptibility. The late-PCV13 period was compared with the pre- and early-PCV13 periods. RESULTS: A total of 2197 episodes were collected-949 in 2008-2009, 609 in 2012-2013 and 639 in 2015-2016. The initial decrease of IPD observed (from 12.3/100 000 to 8.1/100 000; 2008-2009 versus 2012-2013) plateaued in 2015-2016 (8.3/100 000). IPD due to PCV13 serotypes decreased (from 7.7 to 3.5 to 2.3/100 000; p < 0.05), whereas IPD caused by non-PCV13 serotypes increased (from 4.5 to 4.6 to 6.0/100 000; p < 0.05). The most frequent serotypes in the late-PCV13 period were: 8 (15.1%), 3 (10.5%), 12F (7.9%) and 9N (5.4%). These serotypes were related to major genotypes: CC53 (59.8%) and CC404 (30.4%) for serotype 8, CC180 (64.1%) and CC260 (28.1%) for serotype 3, CC989 (91.7%) for serotype 12F and CC67 (84.8%) for serotype 9N. Penicillin-non-susceptibility (21.2%) was associated with serotypes 11A (CC156), 14 (CC156) and 19A (CC320), and macrolide-resistance was related to serotypes 24F and 19A. Rates of pneumococcal meningitis remained stable throughout the periods (ranges 0.9, 0.8 and 1.0/100 000). CONCLUSIONS: The initial decrease of adult IPD observed after PCV13 introduction for children has been balanced by the rise of non-PCV13 serotypes. The spread of antibiotic-resistant lineages related to non-PCV13 serotypes (11A and 24F) could be a threat for the treatment of serious pneumococcal diseases.

Streptococcus pneumoniae ocular infections, prominent role of unencapsulated isolates in conjunctivitis.

The aim of this study was to determine the characteristics and shifts in serotype distribution of pneumococcal isolates causing ocular infections in a region of northern Spain in two periods: 1999-2010 for episodes of conjunctivitis (n = 612) and 1980-2010 for uncommon and more severe non-conjunctival ocular infections (n = 36). All isolates were serotyped and non-typeable isolates were confirmed as unencapsulated by multiplex-PCR of the lytA, ply and cpsA genes. Genotyping was done by pulsed-field gel electrophoresis and multi-locus sequence typing. Most conjunctivitis cases occurred in children under 5 years old (89.5%), and more severe non-conjunctival ocular infections occurred in patients older than 25 years (86.1%). Unencapsulated isolates were detected in 213 conjunctivitis episodes (34.8%) and one non-conjunctival infection (2.8%). Rates of unencapsulated isolates were similar throughout the study. Among 399 conjunctival encapsulated isolates, the most prevalent were serotypes 19A (n = 53), 15B (n = 30), 6A (n = 27), 19F (n = 25), 23F (n = 21) and 6B (n = 17). The most prevalent serotypes in non-conjunctival infections were serotype 3 (n = 4), 23F (n = 4), 6B (n = 3) and 19A (n = 3). Conjunctivitis caused by serotypes included in the hepta-valent pneumococcal conjugate vaccine steadily decreased, accounting for 34.9% (22/63) in 1999-2001, 19.7% (23/117) in 2002-04, 13.6% (33/242) in 2005-07 and 3.2% (6/190) in 2008-10. Among the 213 unencapsulated isolates, 31 different pulsed-field gel electrophoresis patterns were identified. The main clonal complexes (CC) were CC941 (ST941, ST942), CC448 (ST448) and CC344 (ST344, ST3097). CC941 was the predominant CC in 1999-2001, 2002-04 and 2005-07, being replaced by CC448 in 2008-10. The multidrug-resistant CC344 was present throughout the study.

Prevalence and molecular characterization of Streptococcus pneumoniae serotype 6C causing invasive disease in Gipuzkoa, northern Spain, 1990-2009.

The recently discovered pneumococcus serotype 6C was responsible for ten of the 1,530 invasive isolates studied between 1990 and 2009. These ten isolates belonged to seven sequence types (STs) and were isolated only from adult patients: six with bacteremia, three with meningitis, and one with peritonitis. All isolates but one were fully penicillin-susceptible.

Antibody microarray typing, a novel technique for Streptococcus pneumoniae serotyping.

The use of antibody-based miniaturized devices for microbiological applications is a field poorly investigated in the era of more developed molecular amplification techniques. A novel antibody microarray for Streptococcus pneumoniae serotyping was developed, by printing nanolitre volumes of pneumococcal serotype-specific antibodies on multi-well slides. This microarray, which showed high specificity when tested against reference and clinical S. pneumoniae isolates, can be applicable as a faster, cost-effective and accurate serotyping technique for pneumococcal epidemiological studies.

Clonal structure and 21-year evolution of Streptococcus pneumoniae serotype 1 isolates in northern Spain.

This study of 135 serotype 1 pneumococcal isolates (88 invasive and 47 non-invasive), collected between 1987 and 2007, gave eight sequence types (217, 227, 228, 304, 305, 306, 3860 and 3861) that group, using eBurst, into three different lineages and one singleton. The annual incidence of serotype 1 invasive episodes per million inhabitants increased from 1.8 in 1987-1993 to 4.0 in 1994-2000, and to 25.6 in 2001-2007. ST228 was the predominant clone until 1998. ST306 first appeared in 1998 and became the most prevalent sequence type (>80%) after the introduction, in June 2001, of the heptavalent pneumococcal conjugate vaccine.

Invasive Streptococcus pneumoniae infections in children and older adults in the north of Spain before and after the introduction of the heptavalent pneumococcal conjugate vaccine.

In the last two decades, an increasing trend in the incidence of pneumococcal disease in Europe has been reported. We investigated the effect of the use of the heptavalent pneumococcal conjugate vaccine (PCV7) in an area of northern Spain, where all recorded cases of invasive pneumococcal diseases (IPD) were included (n = 450; 91 between 1996-2007 in children aged <5 years and 359 between 1998-2007 in adults aged >64 years). All isolates were serotyped. In children, the overall IPD incidence did not significantly decrease after the introduction, in late 2001, of PCV7. However, the incidence of PCV7 serotypes significantly decreased by 137.2% from 31.59 cases/100,000 population in 1996-2001 to 13.42 in 2002-2007 (95% confidence interval [CI] -27.2 to -342.4%), as did the overall rates of penicillin resistance (from 45.6 to 18.6%) and multiresistance (from 30.3 to 11%). In older adults, the overall IPD incidence showed a non-significant increase due to non-PCV7 serotypes, which seemed to continue a previous trend in our region.

Antimicrobial susceptibilities of amoxycillin-non-susceptible and susceptible isolates among penicillin-non-susceptible Streptococcus pneumoniae.

Antimicrobial susceptibilities of 244 amoxycillin-non-susceptible and 81 amoxycillin-susceptible pneumococcal isolates from 15 Spanish hospitals were determined and clonal relationships were investigated by pulsed-field gel electrophoresis after SmaI restriction. Amoxycillin-non-susceptible isolates exhibited higher rates of resistance to cefuroxime, cefixime, cefpodoxime and clarithromycin, but not to levofloxacin and cefotaxime. Cefditoren exhibited MIC(90) values one dilution lower than those of cefotaxime. Higher numbers of the Spain(14)-5 and Spain(6B)-2 clones, but not the Spain(9V)-3 and Spain(23F)-1 clones, were found among amoxycillin-non-susceptible isolates. Spain(14)-5 was the most problematic clone in terms of antibiotic resistance.

Gipuzkoa, Basque Country, Spain (1984-2004): a hyperendemic area of Q fever.

Overall 1,261 cases of Q fever were diagnosed between 1984 and 2004 in Gipuzkoa (Basque Country, Spain). Most (75.5%) of the cases ocurred in subjects 15-45 years of age. A total of 79.5% of the cases (n = 1003) ocurred between January and June. The annual incidence for acute Q fever in Gipuzkoa was 7.7, 15.8, 9.6, and 5.7 for the periods 1984-1989, 1990-1994, 1995-1999, and 2000-2004, respectively. In 94% of the cases IgM titer was >/=1/256. The most frequent clinical manifestation was pneumonia (79%). Only two cases of chronic Q fever were detected during the 21 years studied.