Vaccine escape of piliated Streptococcus pneumoniae strains

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• 作者：Gili Regev-Yochay^a ; ^b ; ^{gili.regev.y@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; ^{gregev@hsph.harvard.edu" class="auth_mail" title="E-mail the corresponding author} ; Hanaa Jaber^a ; Ayob Hamdan^c ; Muhannad Daana^d ; ^e ; Hanan Nammouz^d ; Amin Thalji^f ; Fuad Jaar^h ; Ziad Abdeenⁱ ; Carmit Rubin^b ; Amit Huppert^g ; Meir Raz^d ; Galia Rahav^a ; on behalf of the PICR study group
• 关键词：PCV7 effects ; Population-based study ; Pilus type-1 ; Pneumococcal vaccines
• 刊名：Vaccine
• 出版年：2016
• 出版时间：27 May 2016
• 年：2016
• 卷：34
• 期：25
• 页码：2787-2792
• 全文大小：892 K

文摘

Type1-pilus proteins were suggested as targets of future protein-based vaccines. Here we studied the effect of pneumococcal-conjugate vaccine (PCV7) implementation on the prevalence of piliated strains in a unique study setting which controls for typical confounders; the Palestinian-Israeli Collaborative Research (PICR).

Methods

Annual cross-sectional surveys of pneumococcal carriage were performed during 2009–2011 among two closely related population that live under different health policies (a) Palestinian-Authority (PA) (n = 1773), where PCV7 was not yet introduced (b) East-Jerusalem (EJ) (n = 983) where PCV7 was rapidly implemented. Clinical data were collected, pneumococci identified and characterized and the presence of Type1-pilus genes was determined by rrgC PCR.

Results

Following PCV7 implementation in EJ, overall carriage prevalence did not change (&sim;30%), but VT7 strains decreased from 61.5% to 33.8%. While prevalence of non-piliated-VT7 isolates decreased from 37% to 10%, p < 0.001, the prevalence of piliated-VT7 strains persisted &sim;25%. Additionally, piliated non-VT13 strains emerged (1–15%, p < 0.001). These changes were not observed in PA. These dynamics were independent of the bacteria's resistance pattern.

Conclusions

A differential effect of PCV7 was observed with a relative resistance of piliated strains to the vaccine. This suggests that Type1-pilus confers an intrinsic advantage for colonization and may be an attractive vaccine target.