ABSTRACT
Human strongyloidiasis research requires a large supply of Strongyloides stercoralis. This can be achieved through in vivo maintenance of Strongyloides stercoralis in Meriones unguiculatus, but isolating a large quantity of Strongyloides stercoralis to establish the colony from an infected patient is too difficult to achieve. Hence, Strongyloides ratti have been used as a model in human strongyloidiasis research. This study describes a successful establishment and maintenance of Strongyloides ratti infection in experimentally immunosuppressed Wistar rats. Large quantities of filariform (iL3) larvae of Strongyloides ratti for research related to human strongyloidiasis have been harvested following this protocol. Molecular detection method based on PCR using species specific primers was used to confirm the species of the harvested infective larvae (iL3). Additionally, the identification of histopathological lesions confirmed the presence of infective larvae (iL3) in the liver and lungs as a result of an increased parasite burden due to hyperinfection and disseminated disease. This pathological presentation was found to be similar to that reported in Strongyloides stercoralis-infected immunocompromised human subjects.
ABSTRACT
In this study, Listeria (L.) monocytogenes isolated from milk and milk products in Kaduna, Nigeria, were subjected to a multiplex PCR assay to identify virulence-associated genes (such as prf A, inl A, hly A, act A, and iap). Of the 36 isolates, 9 (25%) were positive for one or two virulence-associated genes. Based on the sample type, 6 (16.9%) of the isolates that possessed virulence-associated genes were obtained from raw milk, 2 (3.2%) from "Manshanu," and 1 (2.8%) from "Kindrimo." Sequence and phylogenetic analysis based on the 16S rRNA revealed that Nigerian L. monocytogenes isolates (NGA 34A, NGA 35A, NGA 41A, and NGA 38A), when compared with reference L. monocytogenes, were grouped into two distinct clusters, A and B, with sequence (NGA 34A, NGA 35A, and NGA 41A) phylogenetically closer to J1776; N1-011A; R2-502; J1816; and J2-031, whereas L. monocytogenes isolate (NGA 38A) clustered with EDG; J1-220; J1926; J1817; and J2-1091. The separation of the Nigerian L. monocytogenes isolates into linage A (responsible for epidemic listeriosis) and lineage B (responsible for sporadic cases of listeriosis) is of public health concern and that local isolates might have potentials for human food borne listeriosis based on the virulence factors so far identified.
ABSTRACT
This study was conducted to detect and characterize prevalent human group A rotavirus strains from 200 diarrheic children in Sokoto, Nigeria, by ELISA, monoclonal antibody (Mab) serotyping and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) techniques. Rotavirus was detected in 25.5% of the children. The G-serotypes observed in circulation were G4: 16 (59.3%), G1: 4 (14.8%), G2: 3 (11.1%), G3: 3 (11.1%), and G12: 1 (3.7%). The monoclonal antibody (Mab) serotyping detected G1 and G3 but did not detect G4 and G2 serotypes. The Mab typing of the G1 and G3 serotypes was consistent with the result of the RT-PCR. The VP4 genotypes detected were P[6] 3 (13%), P[8] 11 (47.8%), and the rare human P genotype (P[9]), found in 9 patients (39.1%). Nine strains identified with the common G and P combinations were G4 P[8] 5 (56%), G4 P[6] 1 (11%), G1 P[8] 2 (22%), and G3 P[8] 1 (11%), while seven strains with unusual combinations or rare G or P genotypes identified were G12 P[8] 1 (14%), G2 P[8] 2 (29%), and G4 P[9] 4 (57%). To our knowledge this is the first molecular study of human rotavirus and report of rare human G and P serotypes in Sokoto State.
