Phylogeography and resistome of pneumococcal meningitis in West Africa before and after vaccine introduction.

Despite contributing to the large disease burden in West Africa, little is known about the genomic epidemiology of Streptococcus pneumoniae which cause meningitis among children under 5 years old in the region. We analysed whole-genome sequencing data from 185 S. pneumoniae isolates recovered from suspected paediatric meningitis cases as part of the World Health Organization (WHO) invasive bacterial diseases surveillance from 2010 to 2016. The phylogeny was reconstructed, accessory genome similarity was computed and antimicrobial-resistance patterns were inferred from the genome data and compared to phenotypic resistance from disc diffusion. We studied the changes in the distribution of serotypes pre- and post-pneumococcal conjugate vaccine (PCV) introduction in the Central and Western sub-regions separately. The overall distribution of non-vaccine, PCV7 (4, 6B, 9V, 14, 18C, 19F and 23F) and additional PCV13 serotypes (1, 3, 5, 6A, 19A and 7F) did not change significantly before and after PCV introduction in the Central region (Fisher's test P value 0.27) despite an increase in the proportion of non-vaccine serotypes to 40 % (n=6) in the post-PCV introduction period compared to 21.9 % (n=14). In the Western sub-region, PCV13 serotypes were more dominant among isolates from The Gambia following the introduction of PCV7, 81 % (n=17), compared to the pre-PCV period in neighbouring Senegal, 51 % (n=27). The phylogeny illustrated the diversity of strains associated with paediatric meningitis in West Africa and highlighted the existence of phylogeographical clustering, with isolates from the same sub-region clustering and sharing similar accessory genome content. Antibiotic-resistance genotypes known to confer resistance to penicillin, chloramphenicol, co-trimoxazole and tetracycline were detected across all sub-regions. However, there was no discernible trend linking the presence of resistance genotypes with the vaccine introduction period or whether the strain was a vaccine or non-vaccine serotype. Resistance genotypes appeared to be conserved within selected sub-clades of the phylogenetic tree, suggesting clonal inheritance. Our data underscore the need for continued surveillance on the emergence of non-vaccine serotypes as well as chloramphenicol and penicillin resistance, as these antibiotics are likely still being used for empirical treatment in low-resource settings. This article contains data hosted by Microreact

Comparative Characterization of Vibrio cholerae O1 from Five Sub-Saharan African Countries Using Various Phenotypic and Genotypic Techniques.

We used standardized methodologies to characterize Vibrio cholerae O1 isolates from Guinea, Democratic Republic of the Congo (DRC), Togo, Côte d'Ivoire and Mozambique. We investigated 257 human isolates collected in 2010 to 2013. DRC isolates serotyped O1 Inaba, while isolates from other countries serotyped O1 Ogawa. All isolates were biotype El Tor and positive for cholera toxin. All isolates showed multidrug resistance but lacked ciprofloxacin resistance. Antimicrobial susceptibility profiles of isolates varied between countries. In particular, the susceptibility profile of isolates from Mozambique (East-Africa) included resistance to ceftriaxone and was distinctly different to the susceptibility profiles of isolates from countries located in West- and Central-Africa. Molecular subtyping of isolates using pulsed-field gel electrophoresis (PFGE) analysis showed a complex relationship among isolates. Some PFGE patterns were unique to particular countries and clustered by country; while other PFGE patterns were shared by isolates from multiple countries, indicating that the same genetic lineage is present in multiple countries. Our data add to a better understanding of cholera epidemiology in Africa

CHOLTIC Epidémies de choléra au lac Tanganyika induites par les changements climatiques ?

CHOLTI

Some properties of minimal imperfect graphs

SIGLEAvailable from TIB Hannover: RN 4052(91703-OR) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Recurrent Cholera Outbreaks, Democratic Republic of the Congo, 2008–2017

In 2017, the exacerbation of an ongoing countrywide cholera outbreak in the Democratic Republic of the Congo resulted in >53,000 reported cases and 1,145 deaths. To guide control measures, we analyzed the characteristics of cholera epidemiology in DRC on the basis of surveillance and cholera treatment center data for 2008–2017. The 2017 nationwide outbreak resulted from 3 distinct mechanisms: considerable increases in the number of cases in cholera-endemic areas, so-called hot spots, around the Great Lakes in eastern DRC; recurrent outbreaks progressing downstream along the Congo River; and spread along Congo River branches to areas that had been cholera-free for more than a decade. Case-fatality rates were higher in nonendemic areas and in the early phases of the outbreaks, possibly reflecting low levels of immunity and less appropriate prevention and treatment. Targeted use of oral cholera vaccine, soon after initial cases are diagnosed, could contribute to lower case-fatality rates

Map of Africa showing the countries described in the current study.

<p>Map of Africa showing the countries described in the current study.</p

Summary of phenotypic data for <i>V</i>. <i>cholerae</i> O1 isolates.

<p>* Isolates were determined to be resistant to antimicrobial agents at the following MIC breakpoints: ampicillin (Amp), ≥16 μg/ml; ceftriaxone (Cro), ≥2 μg/ml; ≥16 μg/ml; cotrimoxazole (Cot), ≥4 μg/ml; chloramphenicol (Chl), ≥16 μg/ml; nalidixic acid (Nal), ≥32 μg/ml; ciprofloxacin (Cip), ≥2 μg/ml; tetracycline (Tet), ≥8 μg/ml; erythromycin (Ery), ≥4 μg/ml; nitrofurantoin (Nit), ≥64 μg/ml.</p><p>Summary of phenotypic data for <i>V</i>. <i>cholerae</i> O1 isolates.</p

Snapshot of dendrogram of PFGE (<i>Not</i>I digestion) patterns for <i>V</i>. <i>cholerae</i> O1 isolates.

<p>Snapshot of dendrogram of PFGE (<i>Not</i>I digestion) patterns for <i>V</i>. <i>cholerae</i> O1 isolates.</p

Genomic Microevolution of Vibrio cholerae O1, Lake Tanganyika Basin, Africa

Africa’s Lake Tanganyika basin is a cholera hotspot. During 2001–2020, Vibrio cholerae O1 isolates obtained from the Democratic Republic of the Congo side of the lake belonged to 2 of the 5 clades of the AFR10 sublineage. One clade became predominant after acquiring a parC mutation that decreased susceptibility to ciprofloxacin

Wissenschaftliche Begleitung des Vorhabens 'Eindampfanlage zur Behandlung von Deponiesickerwaessern beim Zweckverband Sondermuellplaetze Mittelfranken (ZVSMM) Abschlussbericht

Available from TIB Hannover: RN 5905(2268) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman