Sero-epidemiological evaluation of clonal diversity and antimicrobial susceptibility patterns among Neisseria meningitidis isolates from epidemic cases in Jigawa State, Nigeria

A Uwah, B Iwalokun, O Badaru, Y Gbadegesin



A total of 33 Neisseria culture-positive cerebrospinal fluid (CSF) samples from apparently ill patients during a meningococcal outbreak in Jigawa State, Nigeria were subjected to serogroup, serotype identifications schemes using agglutination and dot blot techniques. Antibiotic susceptibility patterns of the recovered Neisseria meningitidis isolates were also determined.
Seventeen (51.5%), 8 (24.2%), 3 (9.1%) and 5 (15.2%) of the Neisseria isolates belonged to A, B, C and W135 serogroups. Fifteen (N. meningitides A = 8; B = 2; C = 3; W135 = 3) were of serotype 2a, while 4 distinct serosubtypes: P1.5, 2 (57.6%), P1.9 (6.0%), P1.14 (6.0%) and P1.7, 1(15.2%) were found among 28 clones.
The proportions of serogroup A – associated cases, serotyppe 2a and serosubtype P.15, 2 were significant (P < 0.05) compared to other related parameters. While acquisition of meningococcal disease was neither age nor sex dependent (P > 0.05).
Multilocus enzyme electrophoretic typing further stratified the W135 isolates as members of the ET-37 complex. Five (15.2%), 6 (18.2%) and 7 (21.2%) of the 33 culture–positive isolates displayed resistance to ampicillin and chlorampehnicol and intermediate resistance to penicillin.
Resistance pattern characterization further revealed monoresistance to trimethoprim-sulphamethazole (TMP) by 20 isolates and multiresistance with equal predominance (2 each) of patterns: Pen AmpChlTMP, PenAmpTMP, AmpTMP covering all the serogroups.
Three of the five W135, 6 of 17 A and 1 of 8 C serogroups were β–lactamase positive, while enzyme expression was not observed among the B isolates.

African Journal of Clinical and Experimental Microbiology Vol. 9 (1) 2008: pp. 2-18

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