THE ROLE OF LISTERIA MONOCYTOGENES AND OTHER BACTERIA IN MENINGITIS AND SPONTANEOUS ABORTION IN SOME TOWNS IN NORTHERN NIGERIA

The involvement of Listeria monocytogenes in bacterial meningitis and spontaneous abortion in some towns in northern Nigeria was investigated. Three hundred cerebrospinalfluid (CSF) samples, 300 blood and 300 placenta swab samples were collected from meningitis and spontaneous abortion patients in the study area of Bauchi, Jos and Kano. Three hundred nono (a fermented milk product) samples were also collected from milk hawkers at various locations in the study areas. The samples were inoculated first into Listeria enrichment broth. Incubation was at 37o C, followed by cold enrichment at OOC for samples that did not yield any growth at 370C. Furthersub- inoculations were made on Listeria selective agar. Parallel inoculation of the samples was also made on blood, chocolate and McConkey agar media using standard bacteriological methods. Listeria-like organisms were subjected to biochemical and serological investigations using type 1a, 4b and polyvalent sera supplied by Difco laboratories (Detroit, Michigan). The bacterial isolates from the CSF samples included Neisseria meningitidis, Streptococcus pneumoniae, Escherichia coli, Staphylococcus aureus and Listeria monocytogenes. They had the following percentage frequencies of occurrence: 48.8, 16.56, 11.04, 7.36 and 5.58 %, respectively. Furthermore, Enterococcus faecalis, Proteus mirabilis, E. coli, and L. monocytogenes were some of the bacteria isolated from the placenta swabs and blood samples. They had the following percentage frequencies of occurrence: 30.43, 15.65, 13.9 and 12.20% respectively. L. monocytogenes was not isolated from nono samples. However, a simple Listeria selective agar medium, which contained a combination of colistin (1 mg/100 ml) and cefuroxime (2 mg/100ml), enhanced the growth of L. monocytogenes and inhibited other gram positive  and gram negative bacteria. L. monocytogenes contributed to the burden of bacterial meningitis and spontaneous abortion in the study towns.