Persistence of two genotypes of Neisseria gonorrhoeae during transmission.

Isolates of Neisseria gonorrhoeae were tested using a highly discriminatory typing method, opa typing, to examine the genetic diversity over a 2-year study period of isolates from all consecutive patients with gonorrhea attending the Genitourinary Medicine clinic in Sheffield, United Kingdom. Two opa genotypes were detected throughout the 2-year time period and comprised 41% of all strains tested. The persistence of two opa types was investigated further to determine the apparent genetic stability, by examining the ability of isolates to undergo intragenic and intergenic recombination and mutation in vitro. Intragenic recombination or mutation involving the opa genes of N. gonorrhoeae in the selected isolates was not detected, but intergenic recombination did occur. opa genes of N. gonorrhoeae in vivo appear to diversify primarily through intergenic recombination. Intergenic recombination in vivo would require the presence of a mixed gonococcal infection, in which an individual is concurrently colonized with more than one strain of N. gonorrhoeae. We propose that the level of diversity of opa genotypes in a population is linked to the degree of sexual mixing of individuals and the incidence of mixed infections of N. gonorrhoeae

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field