Gonorrhea is a common bacterial infection that is transmitted primarily by sexual contact. Gonococcal infections have an epidemiological pattern characterized by the concentration of infections in social or geographically defined communities termed """"""""core groups"""""""". These """"""""core groups"""""""" have been proposed as reservoirs for the continued transmission of infections within communities, and therefore, understanding the biological nature of the constituent organisms is important for public health control strategies. We propose to examine the molecular evolution of Neisseria gonorrhea within a community over time and in relation to epidemiological information pertaining to the host individuals. This is a collaborative effort between two experts in infectious disease and epidemiology of gonorrhea and a population geneticist. Two molecular typing methods will be used to characterize gonococcal isolates: por gene sequencing and multi-locus sequence typing (MLST) scheme, in which alleles at six housekeeping genes are characterized by sequencing approximately 500 bp internal fragments of the genes. The study has three main objectives The first is to determine temporal trends in the population genetic structure of N. gonorrhea over a 20-year period in a high prevalence community, Baltimore, MD. The second is to correlate changes in population genetic parameters with epidemiological information pertaining to the host individual's residence in a """"""""core"""""""" or """"""""peripheral"""""""" region. Our major hypothesis is that higher levels of genetic diversity, more intense selection pressure on the por gene, a positive growth rate, and a higher recombination rate relative to the peripheral population will characterize the population genetic structure of N. gonorrhea in the core.
The third aim i s to determine whether gender, age, or disseminated versus local infection influences the population genetic structure of N. gonorrhea.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI050217-05
Application #
7021462
Study Section
Genetics Study Section (GEN)
Program Officer
David, Hagit S
Project Start
2002-03-01
Project End
2008-02-28
Budget Start
2006-03-01
Budget End
2008-02-28
Support Year
5
Fiscal Year
2006
Total Cost
$545,144
Indirect Cost
Name
Johns Hopkins University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Tazi, Loubna; Perez-Losada, Marcos; Gu, Weiming et al. (2010) Population dynamics of Neisseria gonorrhoeae in Shanghai, China: a comparative study. BMC Infect Dis 10:13
Perez-Losada, Marcos; Crandall, Keith A; Bash, Margaret C et al. (2007) Distinguishing importation from diversification of quinolone-resistant Neisseria gonorrhoeae by molecular evolutionary analysis. BMC Evol Biol 7:84
Perez-Losada, Marcos; Crandall, Keith A; Zenilman, Jonathan et al. (2007) Temporal trends in gonococcal population genetics in a high prevalence urban community. Infect Genet Evol 7:271-8
Perez-Losada, Marcos; Porter, Megan L; Tazi, Loubna et al. (2007) New methods for inferring population dynamics from microbial sequences. Infect Genet Evol 7:24-43
Perez-Losada, Marcos; Christensen, Ryan G; McClellan, David A et al. (2006) Comparing phylogenetic codivergence between polyomaviruses and their hosts. J Virol 80:5663-9
Crandall, Keith A; Perez-Losada, Marcos; Christensen, Ryan G et al. (2006) Phylogenomics and molecular evolution of polyomaviruses. Adv Exp Med Biol 577:46-59
Perez-Losada, Marcos; Browne, Emily B; Madsen, Aaron et al. (2006) Population genetics of microbial pathogens estimated from multilocus sequence typing (MLST) data. Infect Genet Evol 6:97-112
Perez-Losada, Marcos; Viscidi, Raphael P; Demma, James C et al. (2005) Population genetics of Neisseria gonorrhoeae in a high-prevalence community using a hypervariable outer membrane porB and 13 slowly evolving housekeeping genes. Mol Biol Evol 22:1887-902
Giles, Julie A; Falconio, Jason; Yuenger, Jeffrey D et al. (2004) Quinolone resistance-determining region mutations and por type of Neisseria gonorrhoeae isolates: resistance surveillance and typing by molecular methodologies. J Infect Dis 189:2085-93
Abdo, Zaid; Crandall, Keith A; Joyce, Paul (2004) Evaluating the performance of likelihood methods for detecting population structure and migration. Mol Ecol 13:837-51

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