Comparative analysis of current diagnostic PCR assays in detecting pathogenic Leptospira isolates from environmental samples

Putative Pathogenic Genes of Leptospira interrogans and Leptospira weilii Isolated from Patients with Acute Febrile Illness

Leptospirosis is an important worldwide tropical disease caused by pathogenic Leptospira spp. The determination of virulence genes is important, as it influences patients' clinical manifestations and clinical outcomes. This case report focused on detecting the pathogenic genes of Leptospira in association with the clinical manifestations of patients at the Hospital Universiti Sains Malaysia, Malaysia, who presented with acute febrile illness. Two cases were found and, to the best of our knowledge, these were the first two cases in Malaysia in which patients presented with febrile illness were associated with successful Leptospira isolation from clinical samples. Both clinical isolates were identified by 16S rRNA sequencing as Leptospira weilii and Leptospira interrogans, respectively, and they were classified as pathogenic Leptospira by the presence of different pathogenic genes, based on a polymerase chain reaction (PCR) amplification of targeted genes. This report emphasizes that different infecting Leptospira species and the presence of different virulence factors cause a slight difference in clinical manifestations and laboratory findings of leptospirosis. Genomic sequencing and annotation revealed the detection of classical leptospiral virulence factor genes that were otherwise missed using PCR for detection of Leptospira weilii genome B208.

Sequence Analysis of LipL41 and LipL21: Prospective Outer Membrane Proteins (OMPs) in Early Diagnosing Leptospirosis

Leptospirosis is a zoonotic disease mostly occurring in tropical climate countries. The etiology of the disease is due to microbes from the genus Leptospira. Higher number of cases reported worldwide indicated the disease is not easily eradicated. Leptospirosis shares the most common febrile symptoms such as dengue, Zika and yellow fever thus making it difficult to differentiate the disease at an early stage. The widely used current detection via PCR, uses the bacterial outer membrane protein (OMP) as their target region. However, the heterogeneity and variation of the genome cause false negative results. Lipoprotein LipL41 is the third most abundant outer membrane lipoprotein among pathogenic species and it is surface exposed and expressed during infection thus making it a suitable candidate in identifying pathogenic Leptospira. LipL21 on the other hand is a potential candidate in identifying the intermediate species. The study aimed in designing suitable PCR primers in identifying pathogenic and intermediate species of Leptospira through bioinformatics analysis on the bacterial OMPs. LipL41 and LipL21 were chosen as the suitable target sequence to be used as PCR primers in detecting the pathogenic and intermediate species, respectively. The designed primers indicated positive feedback upon tested with their respective bacterial DNA extract. These lipoproteins may serve as potential PCR primers to be used with clinical samples in diagnosing leptospirosis.•

The etiology of the illness is due to bacteria from the genus Leptospira.

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PCR utilizes the bacterial external membrane protein (OMP) thus the heterogeneity and variety of the genome cause bogus adverse outcomes.

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The suitable candidates are LipL41, the third most abundant outer membrane lipoprotein, whereas LipL21 is a potential candidate in identifying the intermediate species.