Biology subjects

Kehinde, A.

Publications and source records attributed to Kehinde, A..

2 recordsLinked to original sources

bioRxiv2024

Slow-growing Salmonella enterica Typhi mis-identified as Salmonella Gallinarum in Ibadan, Nigeria

Salmonella enterica serovar Typhi is endemic in Nigeria where S. Gallinarum is rarely reported. Probable S. Gallinarum was blood-cultured from three Ibadan patients within 10-days leading to suspicion of an outbreak. All three isolates were re-identified using VITEK-2, whole genome sequenced on Illumina and Oxford Nanopore platforms and confirmed as S. Typhi genotype 3.1.1. Two isolates from the same household had no single nucleotide polymorphisms, suggesting a point-source, but the third was an independent infection event. The isolates formed small colonies, were negative for motility by hanging drop method, and in Sulphide-Indole-Motility medium at 24h, but positive after 48h incubation. Hybrid genome assemblies revealed chromosomal fragment arrangements with imbalances on either side of ori and ter, which has been shown to slow S. Typhi growth. Suspected S. Gallinarum isolates in typhoid endemic areas should be evaluated biochemically and for motility after extended incubation, and verified by serological or molecular methods. Main contributions of the researchO_LIThis study demonstrates that slow-growing Salmonella Typhi can be mis-identified as S. Gallinarum in resource-limited endemic countries. C_LIO_LIExtended motility testing and confirmatory testing can avoid S. Gallinarum miss-calls. C_LIO_LIThe genetic basis for slow-growth may be chromosomal rearrangements at rrn operons, which are known to occur in S. Typhi C_LI

microbiology↗

bioRxiv2019

Comparative Genomics Shows Differences in the Electron Transport and Carbon Metabolic Pathways of Mycobacterium africanum relative to Mycobacterium tuberculosis and suggests an adaptation to low oxygen tension

The geographically restricted Mycobacterium africanum lineages (MAF) are primarily found in West Africa, where they account for a significant proportion of tuberculosis. Despite this phenomenon, little is known about the co-evolution of these ancient lineages with West Africans. MAF and M. tuberculosis sensu stricto lineages (MTB) differ in their clinical, in vitro and in vivo characteristics for reasons not fully understood. Therefore, we compared genomes of 289 MAF and 205 MTB clinical isolates from the 6 main human-adapted M. tuberculosis complex lineages, for mutations in their Electron Transport Chain and Central Carbon Metabolic pathway in order to explain these metabolic differences. Furthermore, we determined, in silico, whether each mutation could affect the function of genes encoding enzymes in these pathways. We found more mutations with the potential to affect enzymes in these pathways in MAF lineages compared to MTB lineages. We also found that similar mutations occurred in these pathways between MAF and some MTB lineages. Generally, our findings show further differences between MAF and MTB lineages that may have contributed to the MAF clinical and growth phenotype and indicate potential adaptation of MAF lineages to a distinct ecological niche, which we suggest includes areas characterized by low oxygen tension.

microbiology↗