Pathogenic Leptospira interrogans in Jos North Abattoir, Nigeria: Occurrence, serology, and molecular characterization.

Leptospirosis, a neglected zoonotic disease, adversely affects animal, human health, and socioeconomic conditions, particularly in developing countries like Nigeria. This study aimed to determine the occurrence and molecular identification of pathogenic Leptospira spp. among abattoir workers, cattle, and rats in Jos North, Plateau State, Nigeria. Using a cross-sectional study design, a total of 394 samples were collected, including 149 urine samples from abattoir workers, 125 urine samples from cattle bladders, and 120 bladders from trapped rats. Samples were processed and cultured in Ellinghausen McCullough Johnson Harrison (EMJH) medium and examined under a darkfield microscope. Positive cultures were confirmed using the Microscopic Agglutination Test (MAT) and nested Polymerase Chain Reaction (N-PCR) targeted the 16 S rDNA gene. Results revealed a prevalence of 33.76 % for Leptospira spp. across all samples, with the highest occurrence in abattoir workers (13.96 %), followed by rats (13.45 %), and cattle (6.35 %). The MAT showed L. interrogans serovar Hardjo str. Hardjoprajitno as the most prevalent serotype (41.61 %), followed by L. interrogans serovar Icterohaemorrhagiae str. RGA (34.31 %). N-PCR confirmed the presence of pathogenic Leptospira spp., showing bands of 1200 bp. Phylogenetic analysis of the 16 S rDNA gene sequences revealed close similarities to known pathogenic Leptospira strains from Brazil and the USA. The study underscores the significant public health risk posed by leptospirosis in Jos North and highlights the need for improved diagnostic capabilities, increased awareness, and effective control measures to mitigate the disease burden. Enhanced surveillance and preventive strategies are crucial to protect both animal and human health in the region.

Effect of single and combination therapy on methanol extracts of Khaya senegalensis stem bark, Vernonia amygdalina leaves and Garcinia kola seed in Leptospira interrogans-infected mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Pastoralists in Nigeria mix Garcinia kola seed (GK), Khaya senegalensis stem bark (KS), and Vernonia amygdalina leaves (VA) to treat leptospirosis. AIM: To determine the in vitro and in vivo effect on single and combination therapy on Leptospira interrogans-infected mice. MATERIALS AND METHODS: Evaluation of in vitro assay for anti-leptospiral motility of the extracts was carried out in triplicates. For the in vivo assessment, 40 adult male mice inoculated with Leptospira were randomly allocated into 8 groups of 5 mice each. Groups IV-IX were treated with 800 mg/kg b.w. of KS, GK, VA, KS + GK, KS + VA, GK + VA for 5 days. Group I was negative control, II was model control, and III was treated with penicillin (3.7 mg/kg b.w.) intramuscularly. RESULTS: In vitro, at 90 min, all the extracts at 800, 400, and 200 mg/ml showed complete cessation of motility which was significantly (p < 0.05) different when compared to the negative control. A significant (p < 0.05) IC50 of 0.18 mg/ml was recorded with GK when compared to KS (0.40 mg/ml), VA (0.25 mg/ml), and procaine penicillin (0.31 mg/ml). Mean packed cell volume, haemoglobin concentration, and mean corpuscular haemoglobin concentration decreased significantly (p < 0.05) in all infected groups and returned to almost pre-infection values. However, significant leucocytosis (p < 0.05) was observed in group II. AST and ALP showed a significant increase (p < 0.001). Histopathological evaluation showed the extracts to prevent the distortion of normal architecture of the selected organs. CONCLUSION: This study demonstrates the significant potential of Garcinia kola, Khaya senegalensis, and Vernonia amygdalina extracts singly and in combination to combat leptospirosis.