[Genetic characteristics of Neisseria meningitidis strains obtained from healthy carriers during meningococcal infection outbreaks].

AIM: Genetic and antigenic characterization of Neisseria meningitidis strains isolated during meningococcal infection outbreaks from individuals in contact with patients with generalized form of meningococcal infection. MATERIALS AND METHODS: Strains obtained in 2007 - 2009 in Moscow during examination of individuals that were in contact with patients during meningococcal infection outbreaks were analyzed. Multilocus sequence typing, genetic subtyping and typing of VR fragment (FetA) techniques were used. RESULTS: Data regarding investigated strains were submitted to the database at http://pubmlst.org/neisseria/. Previously undescribed sequence types were found in 12 strains, sequence-type could not be determined in 2 strains, 2 strains lacked VR fragment (FetA). Serogroup A meningococci had "P1.5-2,10: F3-5" antigenic profile and belonged to ST-75 and ST-3349 sequence-type, these data does not support the emergence of epidemically significant strains in the territory under surveillance. All typed serogroup C strains and 1 serogroup B strain are of "ST-41/44 complex/Lineage 3" clonal complex. Subtypes of serogroup C meningococci strains match subtypes of strains that cause generalized forms of infection, while serogroup B strains isolated from the carriers and strains isolated from the patients had different antigenic profiles. Ungrouppable strains had notably higher level of genetic and antigenic diversity: only 6 of 16 strains (37.5%) could be sequence-typed using earlier data, all these strains are of clonal complex "ST-53 complex" that consists mostly of strains isolated from the carriers. CONCLUSION. Ratio of meningococci population circulating in Moscow and subpopulation capable of causing generalized form of meningococcal infection (GFMI) is different for meningococci of various serogroups. Ungrouppable strains isolated from the carriers are highly different from strains causing GFMI.

[Genetic characteristics of Haemophilus influenzae type b isolated from children with bacterial meningitis in Moscow in 2007-2009].

AIM: Genetic characterization of 37 strains and CSF samples containing DNA of Haemophilus influenzae type b isolated in Moscow during 2007-2009. MATERIALS AND METHODS: Multilocus sequence-typing method was used and also variant of method for capsule type determination was approbated. RESULTS: Ten sequence types, of which 7 were described in previous studies and 3 were revealed for the first time during this work, were detected in studied sample. ST-6 and ST-92 were the most frequently detected--9 strains (24%) of Hib belonging to each sequence type were revealed. All detected sequence types, except one, belong to clonal complex "ST-6" ("A1/A2"). Obtained data were compared with results of typing of Hib strains isolated in Moscow in 1999-2001. Genetic changes in studied population of Hib are characterized by decreased proportion of Hib belonging to ST-6 (from 54% to 24%) and increased number of sequence types belonging to clonal complex "ST-6" differing from ST-6 on more than one locus of allelic profile (from 2 types [2 strains, 5.4%] to 5 types [9 strains, 24%]). CONCLUSION: In 2007-2009, number of Hib strains with sequence type ST-95 (7 strains, 19%), which is typical for strains circulating in Russia, is markedly increased. Capsule type I was detected in 32 (86.5%) of studied strains, whereas capsule type II--in 5 (13.5%) of studied strains. Capsule type II was detected only in Hib strains with ST-80 sequence type.

[Use of several parametric characteristics for study of epidemic features of meningococcal infection and bacterial meningitis].

UNLABELLED: Continuous surveillance for main indicators of epidemic process of meningococcal infection and etiology of bacterial meningitis. Epidemiologic surveillance was electronically-based and was performed on the basis of specially developed standardized case reporting form. Main parameters of epidemiologic surveillance included 10 indexes. Information on 18,519 cases was obtained from 47 regions of Russian Federation. Organization of personalized registry of patients with meningococcal infection and bacterial meningitis allowed to reveal etiologic structure of the disease, territorial differences in serogroup landscape of clinical isolates of meningococci, shortcomings in laboratory diagnostics as well as features of meningitis caused by pneumococci and Haemophilus influenzae type b. CONCLUSION: Necessity of continuous epidemiologic surveillance for meningococcal infection and bacterial meningitis with mandatory use of modern methods of laboratory diagnostics as well as organization of official registration system for meningitis caused by pneumococci and Haemophilus influenzae type b providing decrease of morbidity and development of vaccination tactics was substantiated.

[Monitoring for Neisseria meningitidis species using sequencing of variable fragments of surface proteins FetA and PorA genes].

AIM: To perform advanced antigenic characterization of meningococci belonging to serogroups A and B and circulating in Moscow according to modern nomenclature of Neisseria meningitidis strains. MATERIALS AND METHODS: Method of typing of "VR" fragment of FetA protein together with methods of genetic subtyping and multilocus sequence typing was used. RESULTS: Detailed information about studied strains was inputed in Internet database--http://pubmlst.org/neisseria/. Typing of serogroup B strains did not allow to define dominating variant of "VR, fragment of FetA protein which is in accordance with subtyping data obtained previously. Serogroup A strains were notable for less variability of "VR" fragment variants: 6 variants were detected. For the majority of serogroup A strains, it was possible to trace connection between belonging of the strain to particular genetic subgroup and its revealed antigenic profile. For strains from genetic subgroup VI, antigenic profile P1.5-2, 10; F1-5 detected in 14(18%) strains was typical, whereas antigenic profile P1.5-2, 10; F3-5 was typical for genetic subgroup X and was detected in 50 (63%) strains. Antigenic profile P1.5-2, 10-67; F3-5 was detected in 5 (6%) strains, and other 10 antigenic profiles were revealed in one strain each. CONCLUSION: Prevalence of strains with antigenic profile P1.5-2, 10; F3-5 is explained by change of predominant genetic subgroup from subgroup VI to subgroup X in Moscow population serogroup A meningococci observed after 2003.