ABSTRACT
This study aimed at characterizing the phenotypic and toxigenic status of circulating strains of cholera during outbreaks in Nigeria, employing molecular typing techniques. Two hundred and one samples of rectal swabs, stool, vomitus, water (from the well, borehole, sachet, stream, and tap) and disinfectants (sodium hypochlorite) were collected from three states in the country. The samples were inoculated on thiosulphate-citrate bile salt-sucrose (TCBS), Cary-Blair transport medium and smeared on glass slides for direct examination. The Vibrio cholerae isolates were serotyped, biotyped, and characterized using PCR of the cytotoxin gene A (ctxA), wbeO1, and wbfO139 gene primer. Of the 201 samples screened, 96 were positive for V. cholerae O1 (48%), with 69 (72%) positive for ctxA gene. The results from this study showed that the circulating strains of cholera in Nigeria were of Ogawa serotype, also observed in other outbreaks in Nigeria (1991, 1992, and 1996). However, the strains were of the Classical biotype and were mainly (72%) ctxA gene-positive. This current investigation has confirmed the production of cholera toxin by the circulating strains, and this could be harnessed for possible cholera vaccine production in Nigeria.
ABSTRACT
Purpose: Schistosomiasis ranks second to malaria among parasitic diseases of socio-economic and public health importance. In Nigeria; urinary schistosomiasis caused by Schistosoma haematobium is endemic. This study aimed at producing an accurate data on the prevalence of urinary schistosomiasis in Apojula; a neglected community located around Oyan Dam; southwest Nigeria; using parasitological and molecular techniques. Methods: Parasitological examinations were carried out on urine samples from 63 participants whose ages ranged between 7 and 63 years. Matched blood and urine samples were also screened for S. hematobium infection by polymerase chain reaction (PCR) amplification of the schistosome Dra1 repeat. Results: of the 63 participants; 33 (52.4) were positive for heamaturia while 6 (9.5) had S. haematobium ova in their urine. PCR amplification of S. haematobium Dra1 repeat from their urine and blood samples showed that 59 (93.65) and 62 (98.4) were infected respectively. Conclusion: There was a high prevalence of S. haematobium infection as detected by PCR amplification of schistosome Dra1 repeat from the urine and blood samples of the study participants. In addition; the PCR was able to detect schistosome infection in cases otherwise shown to be negative by parasitological examinations thereby making them also to receive chemotherapy