Investigation and response to an outbreak of Neisseria meningitidis serogroup Y ST-1466 urogenital infections, Australia.

Abstract: In 2023, an increased number of urogenital and anorectal infections with Neisseria meningitis serogroup Y (MenY) were reported in New South Wales (NSW). Whole genome sequencing (WGS) found a common sequence type (ST-1466), with limited sequence diversity. Confirmed outbreak cases were NSW residents with a N. meningitidis isolate matching the cluster sequence type; probable cases were NSW residents with MenY isolated from a urogenital or anorectal site from 1 July 2023 without WGS testing. Of the 41 cases, most were men (n = 27), of whom six reported recent contact with a female sex worker. Five cases were men who have sex with men and two were female sex workers. Laboratory alerts regarding the outbreak were sent to all Australian jurisdictions through the laboratories in the National Neisseria Network. Two additional states identified urogenital MenY ST-1466 infections detected in late 2023. Genomic analysis showed all MenY ST-1466 sequences were interspersed, suggestive of an Australia-wide outbreak. The incidence of these infections remains unknown, due to varied testing and reporting practices both within and across jurisdictions. Isolates causing invasive meningococcal disease (IMD) in Australia are typed, and there has been no MenY ST-1466 IMD recorded in Australia to end of March 2024. Concerns remain regarding the risk of IMD, given the similarity of these sequences with a MenY ST-1466 IMD strain causing a concurrent outbreak in the United States of America.

A matrix metalloproteinase proenzyme activator produced by articular cartilage.

Matrix metalloproteinases (MMPs) are involved in connective tissue turnover under physiological and pathological conditions. MMP activity is regulated by the requirement for zymogen activation. This report describes a proMMP-3 activator produced by articular cartilage. The activator initiates a step-wise processing of proMMP-3 to generate an array of active species. Sequencing of activation intermediates demonstrated cleavage on the NH2-terminal side of certain basic residues in the MMP-3 propeptide. Metal ion chelators inhibited activator-dependent proteolysis, and activity was restored by low levels of ZnCl2. These catalytic properties suggest similarity to members of the insulinase superfamily of metalloendopeptidases with in vitro specificity for single arginine or paired basic processing sites in a variety of prohormones. Dibasic sites also exist in the propeptides of several MMPs including proMMP-3. This is the first report that cartilage produces a potent MMP proenzyme activator, opening the possibility of a novel intrinsic activation pathway for catabolic processes in this avascular tissue.