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

作者：Marimon J M; Ercibengoa M; Garcia Arenzana J M; Alonso M; Perez Trallero E^*

来源：Clinical Microbiology and Infection, 2013, 19(7): E298-E305.

DOI：10.1111/1469-0691.12196

• Clones
• conjunctivitis
• non-typeable isolates
• PCV7
• pneumococcal ocular infections
• Streptococcus pneumoniae
• unencapsulated isolates
• vaccine

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 5years old (89.5%), and more severe non-conjunctival ocular infections occurred in patients older than 25years (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.

• 出版日期2013-7