A simple manganous chloride and Congo red disc method for differentiating Neisseria gonorrhoeae from Neisseria meningitidis

A novel metal transporter mediating manganese export (MntX) regulates the Mn to Fe intracellular ratio and Neisseria meningitidis virulence

Neisseria meningitidis (Nm) and N. gonorrhoeae (Ng) are adapted to different environments within their human host. If the basis of this difference has not yet been fully understood, previous studies (including our own data) have reported that, unlike Ng, Nm tolerates high manganese concentrations. As transition metals are essential regulators of cell growth and host pathogen interactions, we aimed to address mechanisms of Nm Mn²⁺ tolerance and its pathogenic consequences. Using bioinformatics, gene deletion and heterologous expression we identified a conserved bacterial manganese resistance factor MntX (formerly YebN). The predicted structure suggests that MntX represents a new family of transporters exporting Mn. In the Neisseria genus, this exporter is present and functional in all Nm isolates but it is mutated in a majority of Ng strains and commonly absent in nonpathogenic species. In Nm, Mn²⁺ export via MntX regulates the intracellular Mn/Fe ratio and protects against manganese toxicity that is exacerbated in low iron conditions. MntX is also important for N. meningitidis to resist killing by human serum and for survival in mice blood during septicemia. The present work thus points to new clues about Mn homeostasis, its interplay with Fe metabolism and the influence on N. meningitidis physiology and pathogenicity.

Sexually transmitted diseases in northern Nigeria. Five years' experience in a university teaching hospital clinic

Between 1977 and 1981, 3089 patients attended the sexually transmitted diseases (STD) clinic in Zaria, northern Nigeria. The male-to-female ratio of attenders was 6:1. Postpubertal gonorrhoea accounted for 28.1% of cases, non-specific genital infections for 22.4%, and syphilis for 1.2%. Illiteracy, polygamy, the purdah system, widespread prostitution, and inadequate facilities are factors aiding the spread of these diseases in northern Nigeria.