Biology subjects

Rots, N. Y.

Publications and source records attributed to Rots, N. Y..

2 recordsLinked to original sources

bioRxiv2021

Detection of Neisseria meningitidis in Saliva and Oropharyngeal Samples from College Students

ObjectivesSince conjugated polysaccharide vaccines reduce carriage of vaccine-type Neisseria meningitidis strains, meningococcal carriage is an accepted endpoint in monitoring vaccine effects. We have assessed vaccine-type genogroup carriage prevalence in students at the time of MenACWY vaccine introduction in The Netherlands. In addition, we evaluated the feasibility of saliva sampling and qPCR-based detection method for the surveillance of meningococcal carriage. MethodsPaired saliva and oropharyngeal samples, collected from 299 students, were cultured for meningococcus. The DNA extracted from all bacterial growth was subjected to qPCRs quantifying meningococcal presence and genogroup-specific genes. Samples negative by culture yet positive for qPCR were cultured again for meningococcus. Results for saliva were compared with oropharyngeal samples. ResultsAltogether 74 (25% of 299) students were identified as meningococcal carrier by any method used. Sixty-one students (20%) were identified as carriers with qPCR. The difference between number of qPCR-positive oropharyngeal (n=59) and saliva (n=52) samples was not significant (McNemars test, p=0.07). Meningococci were cultured from 72 students (24%), with a significantly higher (p<0.001) number of oropharyngeal (n=70) compared with saliva (n=54) samples. The prevalence of genogroups A, B, C, W, and Y was none, 9%, 1% and 6%, respectively, and 8% of students carried MenACWY vaccine-type genogroup meningococci. ConclusionsWe show that the detected prevalence of meningococcal carriage between oropharyngeal and saliva samples was nondifferent with qPCR and moreover, detection with both samples was highly concordant. Saliva is easy to collect and when combined with qPCR detection can be considered for meningococcal carriage studies.

microbiology↗

bioRxiv2021

Pneumococcal genetic variability influences age-dependent bacterial carriage

The pneumococcal conjugate vaccine (PCV) primarily reduces disease burden in adults through a reduction in carriage prevalence of invasive serotypes in children. Current vaccine formulations are the same for both adults and children, but tailoring these formulations to age category could optimize vaccine efficacy. Identification of specific pneumococcal genetic factors associated with carriage in younger or older age groups may suggest alternative formulations and contribute to a better mechanistic understanding of immunity. Here, we used whole genome sequencing to dissect pneumococcal variation associated with age. We performed genome sequencing in a large carriage cohort, and conducted a meta-analysis with an existing carriage study. We compiled a dictionary of pathogen genetic variation including serotype, sequence cluster, sequence elements, SNPs, burden combined rare variants, and clusters of orthologous genes (COGs) for each cohort - all of which used in a genome-wide association with host age. Age-dependent colonization had some heritability, though this varied between cohorts (h2 = 0.10, 0.00 - 0.69 95% CI in the first; h2 = 0.46, 0.33 - 0.60 95% CI in the second cohort). We found that serotypes and genetic background (strain) explained most of the heritability in each cohort (h2serotype = 0.06 and h2GPSC = 0.04 in the first; h2 serotype = 0.20 and h2 GPSC = 0.23 in the second cohort). We found one candidate association (p = 1.2x10-9) upstream of an accessory Sec-dependent serine-rich glycoprotein adhesin. Overall, association with age was highly cohort and strain dependent, supporting proposals for a future vaccination strategy which is primarily targeted using serotypes rather than proteins, and is tailored towards specific pathogen populations.

microbiology↗