scholarly journals Genomic Characteristics of Invasive Streptococcus pneumoniae Serotype 1 in New Caledonia Prior to the Introduction of PCV13

2020 ◽  
Vol 14 ◽  
pp. 117793222096210 ◽  
Author(s):  
Mariem Hanachi ◽  
Anmol Kiran ◽  
Jennifer Cornick ◽  
Emna Harigua-Souiai ◽  
Dean Everett ◽  
...  
Keyword(s):  
Population Structure ◽  
Streptococcus Pneumoniae ◽  
Virulence Genes ◽  
New Caledonia ◽  
Disease Outbreaks ◽  
Genomic Diversity ◽  
Whole Genome Sequence ◽  
Serotype 1 ◽  
The Impact ◽  
Sequence Types

Streptococcus pneumoniae serotype 1 is a common cause of global invasive pneumococcal disease. In New Caledonia, serotype 1 is the most prevalent serotype and led to two major outbreaks reported in the 2000s. The pneumococcal conjugate vaccine 13 (PCV13) was introduced into the vaccination routine, intending to prevent the expansion of serotype 1 in New Caledonia. Aiming to provide a baseline for monitoring the post-PCV13 changes, we performed a whole-genome sequence analysis on 67 serotype 1 isolates collected prior to the PCV13 introduction. To highlight the S. pneumoniae serotype 1 population structure, we performed a multilocus sequence typing (MLST) analysis revealing that NC serotype 1 consisted of 2 sequence types: ST3717 and the highly dominant ST306. Both sequence types harbored the same resistance genes to beta-lactams, macrolide, streptogramin B, fluoroquinolone, and lincosamide antibiotics. We have also identified 36 virulence genes that were ubiquitous to all the isolates. Among these virulence genes, the pneumolysin sequence presented an allelic profile associated with disease outbreaks and reduced hemolytic activity. Moreover, recombination hotspots were identified in 4 virulence genes and more notably in the cps locus ( cps2L), potentially leading to capsular switching, a major mechanism of the emergence of nonvaccine types. In summary, this study represents the first overview of the genomic characteristics of S. pneumoniae serotype 1 in New Caledonia prior to the introduction of PCV13. This preliminary description represents a baseline to assess the impact of PCV13 on serotype 1 population structure and genomic diversity.

scholarly journals SeroBA: rapid high-throughput serotyping of Streptococcus pneumoniae from whole genome sequence data

2017 ◽  
Author(s):  
Lennard Epping ◽  
Andries J. van Tonder ◽  
Rebecca A. Gladstone ◽  
Stephen D. Bentley ◽  
Andrew J. Page ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Whole Genome Sequence ◽  
Validation Dataset ◽  
List Type ◽  
Whole Genome ◽  
Link Type ◽  
Computational Performance ◽  
The Impact

ABSTRACTStreptococcus pneumoniae is responsible for 240,000 - 460,000 deaths in children under 5 years of age each year. Accurate identification of pneumococcal serotypes is important for tracking the distribution and evolution of serotypes following the introduction of effective vaccines. Recent efforts have been made to infer serotypes directly from genomic data but current software approaches are limited and do not scale well. Here, we introduce a novel method, SeroBA, which uses a hybrid assembly and mapping approach. We compared SeroBA against real and simulated data and present results on the concordance and computational performance against a validation dataset, the robustness and scalability when analysing a large dataset, and the impact of varying the depth of coverage in the cps locus region on sequence-based serotyping. SeroBA can predict serotypes, by identifying the cps locus, directly from raw whole genome sequencing read data with 98% concordance using a k-mer based method, can process 10,000 samples in just over 1 day using a standard server and can call serotypes at a coverage as low as 10x. SeroBA is implemented in Python3 and is freely available under an open source GPLv3 license from: https://github.com/sanger-pathogens/seroba.DATA SUMMARYThe reference genome Streptococcus pneumoniae ATCC 700669 is available from National Center for Biotechnology Information (NCBI) with the accession number: FM211187Simulated paired end reads for experiment 2 have been deposited in FigShare: https://doi.org/10.6084/m9.figshare.5086054.v1Accession numbers for all other experiments are listed in Supplementary Table S1 and Supplementary Table S2.I/We confirm all supporting data, code and protocols have been provided within the article or through supplementary data files. ⊠IMPACT STATEMENTThis article describes SeroBA, a A-mer based method for predicting the serotypes of Streptococcus pneumoniae from Whole Genome Sequencing (WGS) data. SeroBA can identify 92 serotypes and 2 subtypes with constant memory usage and low computational costs. We showed that SeroBA is able to reliably predict serotypes at a depth of coverage as low as 10x and is scalable to large datasets.

scholarly journals Temporal changes in nasopharyngeal carriage of Streptococcus pneumoniae serotype 1 genotypes in healthy Gambians before and after the 7-valent pneumococcal conjugate vaccine

2014 ◽  
Author(s):  
Chinelo Ebruke ◽  
Anna Roca ◽  
Uzochukwu Egere ◽  
Ousainou Darboe ◽  
Philip C Hill ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Epidemiological Studies ◽  
Temporal Changes ◽  
Nasopharyngeal Carriage ◽  
Post Vaccination ◽  
Period 2 ◽  
Serotype 1 ◽  
Pneumococcal Serotype ◽  
The Impact ◽  
Vaccination Period

Streptococcus pneumoniae serotype 1 is one of the leading causes of invasive pneumococcal disease. However this invasive serotype is hardly found in nasopharyngeal asymptomatic carriage and therefore large epidemiological studies are needed to assess the dynamics of serotype 1 infection. Within the context of a large cluster randomized trial conducted in rural Gambia to assess the impact of PCV-7 vaccination on nasopharyngeal carriage, we present an ancillary study describing the prevalence of nasopharyngeal carriage of pneumococcal serotype 1 and temporal changes of its more frequent genotypes. Nasopharyngeal swabs (NPS) were collected before PCV-7 vaccination (December 2003-May 2004) and up to 30 months after PCV-7 vaccination (post-vaccination periods 1 to 3: July 2006 – March 2007; April 2007 – March 2008 and April 2008 – Feb 2009). S. pneumoniae serotype 1 were genotyped by MLST. Serotype 1 was recovered from 87 (0.71%) of 12,319 NPS samples collected. In the pre-vaccination period, prevalence of serotype 1 was 0.47% in both study arms. In the post-vaccination periods, prevalence in the fully vaccinated villages ranged between 0.08% in period 1 and 0.165% in period 2; while prevalence in partly vaccinated villages was between 0.17% in period 3 and 1.34% in period 2. Overall four different genotypes were obtained with ST3081 the most prevalent (60.71%) followed by ST618 929.76%). ST3081 was found only in post-vaccination period 2 and 3 while ST618 had disappeared in post-vaccination period 3. Distribution of these major genotypes was similar in both study arms.Emergence of ST3081 and concomitant disappearance of ST618 may suggest a change in the molecular epidemiology of pneumococcal serotype 1 in this region. This change is not likely to be associated with the introduction of PCV-7 which lacks serotype 1 as it was observed simultaneously in both study arms. Future population-based epidemiological studies will provide further evidence of substantive changes in the pneumococcal serotype 1 epidemiology and the likely mechanisms.

scholarly journals Characterization of Streptococcus pneumoniae strains causing invasive infections using whole-genome sequencing

2020 ◽  
Vol 97 (2) ◽  
pp. 113-118 ◽  
Author(s):  
Konstantin O. Mironov ◽  
Vitaly I. Korchagin ◽  
Yuliya V. Mikhailova ◽  
Yurii G. Yanushevich ◽  
Andrey A. Shelenkov ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Pneumococcal Infection ◽  
Whole Genome ◽  
Multicenter Studies ◽  
Serotype 1 ◽  
Invasive Infections ◽  
Sequence Types

Purpose: antigenic and genetic characterization of Streptococcus pneumoniae strains isolated from patients with invasive forms of pneumococcal infection using whole-genome sequencing.Materials and Methods. The study was performed on 46 S. pneumoniae strains isolated during the PEHASus multicenter studies in 2015-2018. Sequencing was performed using Illumina protocols and equipment. The SPAdes, SeroBA, PneumoCaT software were used for data processing, as well as BIGSdb software (PubMLST.org).Results and Discussion. Whole-genome sequences of strains were obtained; the information was entered into the PubMLST database (id: 51080-51125). Ten (21%) strains were found to have serotype 3. Five (11%) strains belonged to serotype 19F and five to serogroup 6; two of them belonged to serotype 6A; one strain had 6B and 1 had 6BE serotype; 1 strain showed discordant result (6A or 6BE). Serotype 15B was identified in 3 (6.5%) strains. Serotypes 7F, 8, 9V, 14, 22F, 23F and 28A were identified in two strains each; serotypes 1, 4, 9N, 10C, 12F, 18C, 35F, 37 and 38 were found once. The proportion of strains with serotypes included in PCV13 and PPV23 vaccines was 65% and 80%, respectively. 36 sequence types were found in strains; out of them, 6 sequence types were found for the first time. A dominant sequence type or clone complexes could not be identified using multilocus sequence typing except for serotype 3 strains. The inability to identify clonal complexes is in congruence with the previously obtained data on the absence of S. pneumoniae clones associated with pneumococcal meningitis in Russia.Conclusion. The information about serotypes of S. pneumoniae causing invasive infections together with epidemiologic data about strain sources and vaccination allows us to evaluate the effectiveness of pneumococcal vaccines and provide information for improving the PCR-based routine serotyping.

scholarly journals Fine-scale population structure and demographic history of British Pakistanis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Elena Arciero ◽  
Sufyan A. Dogra ◽  
Daniel S. Malawsky ◽  
Massimo Mezzavilla ◽  
Theofanis Tsismentzoglou ◽  
...  
Keyword(s):  
Population Structure ◽  
Disease Risk ◽  
Demographic History ◽  
Population History ◽  
Genomic Diversity ◽  
Fine Scale ◽  
Effective Population ◽  
Scale Population ◽  
The Impact ◽  
British Pakistanis

AbstractPrevious genetic and public health research in the Pakistani population has focused on the role of consanguinity in increasing recessive disease risk, but little is known about its recent population history or the effects of endogamy. Here, we investigate fine-scale population structure, history and consanguinity patterns using genotype chip data from 2,200 British Pakistanis. We reveal strong recent population structure driven by the biraderi social stratification system. We find that all subgroups have had low recent effective population sizes (Ne), with some showing a decrease 15‒20 generations ago that has resulted in extensive identity-by-descent sharing and homozygosity, increasing the risk of recessive disorders. Our results from two orthogonal methods (one using machine learning and the other coalescent-based) suggest that the detailed reporting of parental relatedness for mothers in the cohort under-represents the true levels of consanguinity. These results demonstrate the impact of cultural practices on population structure and genomic diversity in Pakistanis, and have important implications for medical genetic studies.

scholarly journals Temporal changes in nasopharyngeal carriage of Streptococcus pneumoniae serotype 1 genotypes in healthy Gambians before and after the 7-valent pneumococcal conjugate vaccine

2014 ◽  
Author(s):  
Chinelo Ebruke ◽  
Anna Roca ◽  
Uzochukwu Egere ◽  
Ousainou Darboe ◽  
Philip C Hill ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Epidemiological Studies ◽  
Temporal Changes ◽  
Nasopharyngeal Carriage ◽  
Post Vaccination ◽  
Period 2 ◽  
Serotype 1 ◽  
Pneumococcal Serotype ◽  
The Impact ◽  
Vaccination Period

Streptococcus pneumoniae serotype 1 is one of the leading causes of invasive pneumococcal disease. However this invasive serotype is hardly found in nasopharyngeal asymptomatic carriage and therefore large epidemiological studies are needed to assess the dynamics of serotype 1 infection. Within the context of a large cluster randomized trial conducted in rural Gambia to assess the impact of PCV-7 vaccination on nasopharyngeal carriage, we present an ancillary study describing the prevalence of nasopharyngeal carriage of pneumococcal serotype 1 and temporal changes of its more frequent genotypes. Nasopharyngeal swabs (NPS) were collected before PCV-7 vaccination (December 2003-May 2004) and up to 30 months after PCV-7 vaccination (post-vaccination periods 1 to 3: July 2006 – March 2007; April 2007 – March 2008 and April 2008 – Feb 2009). S. pneumoniae serotype 1 were genotyped by MLST. Serotype 1 was recovered from 87 (0.71%) of 12,319 NPS samples collected. In the pre-vaccination period, prevalence of serotype 1 was 0.47% in both study arms. In the post-vaccination periods, prevalence in the fully vaccinated villages ranged between 0.08% in period 1 and 0.165% in period 2; while prevalence in partly vaccinated villages was between 0.17% in period 3 and 1.34% in period 2. Overall four different genotypes were obtained with ST3081 the most prevalent (60.71%) followed by ST618 929.76%). ST3081 was found only in post-vaccination period 2 and 3 while ST618 had disappeared in post-vaccination period 3. Distribution of these major genotypes was similar in both study arms.Emergence of ST3081 and concomitant disappearance of ST618 may suggest a change in the molecular epidemiology of pneumococcal serotype 1 in this region. This change is not likely to be associated with the introduction of PCV-7 which lacks serotype 1 as it was observed simultaneously in both study arms. Future population-based epidemiological studies will provide further evidence of substantive changes in the pneumococcal serotype 1 epidemiology and the likely mechanisms.

scholarly journals Population Structure of Non-ST6 Listeria monocytogenes Isolated in the Red Meat and Poultry Value Chain in South Africa

2020 ◽  
Vol 8 (8) ◽  
pp. 1152
Author(s):  
Itumeleng Matle ◽  
Thendo Mafuna ◽  
Evelyn Madoroba ◽  
Khanyisile R. Mbatha ◽  
Kudakwashe Magwedere ◽  
...  
Keyword(s):  
South Africa ◽  
Population Structure ◽  
South African ◽  
Value Chain ◽  
Meat Products ◽  
Genomic Diversity ◽  
Whole Genome Sequence ◽  
Processed Meat ◽  
Main Lineage ◽  
High Level

Meat products have been implicated in many listeriosis outbreaks globally, however there is a dearth of information on the diversity of L. monocytogenes isolates circulating in food products in South Africa. The aim of this study was to investigate the population structure of L. monocytogenes isolated in the meat value chain within the South African market. Based on whole-genome sequence analysis, a total of 217 isolates were classified into two main lineage groupings namely lineages I (n = 97; 44.7%) and II (n = 120; 55.3%). The lineage groups were further differentiated into IIa (n = 95, 43.8%), IVb (n = 69, 31.8%), IIb (n = 28, 12.9%), and IIc (n = 25, 11.5%) sero-groups. The most abundant sequence types (STs) were ST204 (n = 32, 14.7%), ST2 (n = 30, 13.8%), ST1 (n = 25, 11.5%), ST9 (n = 24, 11.1%), and ST321 (n = 21, 9.7%). In addition, 14 clonal complex (CCs) were identified with over-representation of CC1, CC3, and CC121 in “Processed Meat-Beef”, “RTE-Poultry”, and “Raw-Lamb” meat categories, respectively. Listeria pathogenic islands were present in 7.4% (LIPI-1), 21.7% (LIPI-3), and 1.8% (LIPI-4) of the isolates. Mutation leading to premature stop codons was detected in inlA virulence genes across isolates identified as ST121 and ST321. The findings of this study demonstrated a high-level of genomic diversity among L. monocytogenes isolates recovered across the meat value chain control points in South Africa.

scholarly journals Fine-scale population structure and demographic history of British Pakistanis

2020 ◽  
Author(s):  
Elena Arciero ◽  
Sufyan A. Dogra ◽  
Massimo Mezzavilla ◽  
Theofanis Tsismentzoglou ◽  
Qin Qin Huang ◽  
...  
Keyword(s):  
Population Structure ◽  
Disease Risk ◽  
Demographic History ◽  
Population History ◽  
Genomic Diversity ◽  
Fine Scale ◽  
Effective Population ◽  
Scale Population ◽  
The Impact ◽  
British Pakistanis

AbstractPrevious genetic and public health research in the Pakistani population has focused on the role of consanguinity in increasing recessive disease risk, but little is known about its recent population history or the effects of endogamy. Here, we investigate fine-scale population structure, history and consanguinity patterns using genetic and questionnaire data from >4,000 British Pakistani individuals, mostly with roots in Azad Kashmir and Punjab. We reveal strong recent population structure driven by the biraderi social stratification system. We find that all subgroups have had low effective population sizes (Ne) over the last 50 generations, with some showing a decrease in Ne 15-20 generations ago that has resulted in extensive identity-by-descent sharing and increased homozygosity. Using new theory, we show that the footprint of regions of homozygosity in the two largest subgroups is about twice that expected naively based on the self-reported consanguinity rates and the inferred historical Ne trajectory. These results demonstrate the impact of the cultural practices of endogamy and consanguinity on population structure and genomic diversity in British Pakistanis, and have important implications for medical genetic studies.

scholarly journals Identification, prevalence and population structure of non-typable Streptococcus pneumoniae in carriage samples isolated from preschoolers attending day-care centres

Microbiology ◽  
2006 ◽  
Vol 152 (2) ◽  
pp. 367-376 ◽  
Author(s):  
Raquel Sá-Leão ◽  
Alexandra S. Simões ◽  
Sónia Nunes ◽  
Natacha G. Sousa ◽  
Nelson Frazão ◽  
...  
Keyword(s):  
Population Structure ◽  
Multidrug Resistance ◽  
Streptococcus Pneumoniae ◽  
Southern Blotting ◽  
Distinct Group ◽  
Specific Group ◽  
Resistance To Penicillin ◽  
Day Care Centres ◽  
Quellung Reaction ◽  
Sequence Types

The authors aimed to get insights into the population structure of non-(sero)typable pneumococci (NTPn), a specific group of natural atypical pneumococci whose identification is often difficult, and which has remained insufficiently studied. A total of 265 presumptive NTPn, isolated between 1997 and 2003 from the nasopharynx of children, were characterized. Strains were confirmed to be pneumococci on the basis of bile solubility, and PCR detection or Southern blotting hybridization of lytA and psaA, genes ubiquitous in this species. Multilocus sequence typing (MLST) was used to exclude two isolates that gave ambiguous results. Non-typability was confirmed by the Quellung reaction using Omniserum. A total of 213 isolates were considered to be true NTPn. The molecular analysis of the true NTPn by PFGE and MLST showed that this population was genetically diverse, although a dominant cluster, accounting for 66 % of the isolates, was identified. Antimicrobial resistance was observed in most genetic backgrounds, and multidrug resistance to penicillin, erythromycin, clindamycin, tetracycline and sulfamethoxazole-trimethoprim was associated with strains belonging to the dominant cluster. Comparison with PFGE fingerprints and sequence types of large collections of serotypable strains showed that the genetic backgrounds of all but two NTPn were different from those found in serotypable strains. In addition, we found that NTPn strains with similar genetic backgrounds to those identified in our study had been isolated from disease sources in other countries. These observations seem to indicate that NTPn have diverse genetic backgrounds and may have evolved as a distinct group of pneumococcal isolates.

scholarly journals Genomic diversity of Escherichia coli isolates from non-human primates in the Gambia

2020 ◽  
Author(s):  
Ebenezer Foster-Nyarko ◽  
Nabil-Fareed Alikhan ◽  
Anuradha Ravi ◽  
Gaëtan Thilliez ◽  
Nicholas Thomson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Population Structure ◽  
Antimicrobial Resistance ◽  
Genome Sequencing ◽  
Host Species ◽  
The Gambia ◽  
Genomic Diversity ◽  
Whole Genome ◽  
E Coli ◽  
Sequence Types

AbstractIncreasing contact between humans and non-human primates provides an opportunity for the transfer of potential pathogens or antimicrobial resistance between host species. We have investigated genomic diversity, and antimicrobial resistance in Escherichia coli isolates from four species of non-human primate in the Gambia: Papio papio (n=22), Chlorocebus sabaeus (n=14), Piliocolobus badius (n=6) and Erythrocebus patas (n=1). We performed Illumina whole-genome sequencing on 101 isolates from 43 stools, followed by nanopore long-read sequencing on eleven isolates. We identified 43 sequence types (STs) by the Achtman scheme (ten of which are novel), spanning five of the eight known phylogroups of E. coli. The majority of simian isolates belong to phylogroup B2—characterised by strains that cause human extraintestinal infections—and encode factors associated with extraintestinal disease. A subset of the B2 strains (ST73, ST681 and ST127) carry the pks genomic island, which encodes colibactin, a genotoxin associated with colorectal cancer. We found little antimicrobial resistance and only one example of multi-drug resistance among the simian isolates. Hierarchical clustering showed that simian isolates from ST442 and ST349 are closely related to isolates recovered from human clinical cases (differences in 50 and seven alleles respectively), suggesting recent exchange between the two host species. Conversely, simian isolates from ST73, ST681 and ST127 were distinct from human isolates, while five simian isolates belong to unique core-genome ST complexes—indicating novel diversity specific to the primate niche. Our results are of public health importance, considering the increasing contact between humans and wild non-human primates.Impact statementLittle is known about the population structure, virulence potential and the burden of antimicrobial resistance among Escherichia coli from wild non-human primates, despite increased exposure to humans through the fragmentation of natural habitats. Previous studies, primarily involving captive animals, have highlighted the potential for bacterial exchange between non-human primates and humans living nearby, including strains associated with intestinal pathology. Using multiple-colony sampling and whole-genome sequencing, we investigated the strain distribution and population structure of E. coli from wild non-human primates from the Gambia. Our results indicate that these monkeys harbour strains that can cause extraintestinal infections in humans. We document the transmission of virulent E. coli strains between monkeys of the same species sharing a common habitat and evidence of recent interaction between strains from humans and wild non-human primates. Also, we present complete genome assemblies for five novel sequence types of E. coli.Author notesAll supporting data, code and protocols have been provided within the article or through supplementary data files. Nine supplementary figures and six supplementary files are available with the online version of this article.AbbreviationsExPEC, Extraintestinal pathogenic Escherichia coli; ST, Sequence type; AMR, Antimicrobial resistance; MLST, Multi-locus sequence typing; VFDB, Virulence factors database; SNP, single nucleotide polymorphism; SPRI, Solid phase reversible immobilisation.Data summaryThe raw sequences and polished assemblies from this study are available in the National Center for Biotechnology Information (NCBI) Short Read Archive, under the BioProject accession number PRJNA604701. The full list and characteristics of these strains and other reference strains used in the analyses are presented in Table 1 and Supplementary Files 1-4 (available with the online version of this article).

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