[Frequency of diseases caused by group A streptococci among invasive infections of soft tissues and characteristics of the causative agent].

AIM: Determine frequency of diseases caused by group A streptococci (GAS) among invasive infections of soft tissues; identify emm-types of the isolated streptococci, determine the presence of bacteriophage integrases and toxin genes in their genomes. MATERIALS AND METHODS: 4750 case histories of patients with soft tissue infections of the purulent-surgical department of the 23rd City Clinical Hospital.of Moscow "Medsantrud" in 2008 - 2011 were analyzed. 46 strains of GAS isolated from patients with invasive streptococcus infection (ISI) were studied. GAS identification was carried out by latex-agglutination method. GAS emm-type was determined by molecular-genetic methods, as well as the presence of bacteriophage integrases int2, int3, int4, int5, int6, int7, int49, bacteriophage toxins speA, speI, sla, speC/J, speL, speH, speC, ssa and speB gene present on the chromosomal DNA. RESULTS: 132 cases (2.8%) were attributed to invasive infections. In 46 cases of invasive infections (35%) GAS were isolated. 22 different emm-types of invasive GAS strains were detected. Only speB gene among all the toxin genes (as well as the expression of the gene--SpeB toxin) was detected in all the strains, whereas sla and speI genes were not detected in any of the strains. Genes of the other toxins (ssa, speL, speC, speA, speH, speC/J) occurred in a number of strains. Genes of phage integrases were detected among all the strains however in varying combinations (from 1 to 4 genes). CONCLUSION: Invasive infections caused by GAS are more frequently spread than had been previously assumed and a high degree of genetic heterogeneity of invasive GAS strains was detected.

[The Molecular and Biological Patterns Underlying Sustained SARS-CoV-2 Circulation in the Human Population].

INTRODUCTION: For four years, SARS-CoV-2, the etiological agent of COVID-19, has been circulating among humans. By the end of the second year, an absence of immunologically naive individuals was observed, attributable to extensive immunization efforts and natural viral exposure. This study focuses on delineating the molecular and biological patterns that facilitate the persistence of SARS-CoV-2, thereby informing predictions on the epidemiological trajectory of COVID-19 toward refining pandemic countermeasures. The aim of this study was to describe the molecular biological patterns identified that contribute to the persistence of the virus in the human population. MATERIALS AND METHODS: For over three years since the beginning of the COVID-19 pandemic, molecular genetic monitoring of SARS-CoV-2 has been conducted, which included the collection of nasopharyngeal swabs from infected individuals, assessment of viral load, and subsequent whole-genome sequencing. RESULTS: We discerned dominant genetic lineages correlated with rising disease incidence. We scrutinized amino acid substitutions across SARS-CoV-2 proteins and quantified viral loads in swab samples from patients with emerging COVID-19 variants. Our findings suggest a model of viral persistence characterized by 1) periodic serotype shifts causing substantial diminutions in serum virus-neutralizing activity (> 10-fold), 2) serotype-specific accrual of point mutations in the receptor-binding domain (RBD) to modestly circumvent neutralizing antibodies and enhance receptor affinity, and 3) a gradually increasing amount of virus being shed in mucosal surfaces within a single serotype. CONCLUSION: This model aptly accounts for the dynamics of COVID-19 incidence in Moscow. For a comprehensive understanding of these dynamics, acquiring population-level data on immune tension and antibody neutralization relative to genetic lineage compositions is essential.

[Invasive streptococcal (group A) infection of soft tissues in a Moscow surgical hospital].

AIM: To study features and risk factors of soft tissue's invasive streptococcal infection in surgical unit's patients: a) emm-types of the most often recovered streptococcus; b) human immune response for streptococcal antigens (streptolysin-O and the group A carbohydrate antigen); c) main patient's conditions that complicate the course of soft tissue's streptococcal infection. PATIENTS AND METHODS: 101 surgical unit's patients with soft tissue's infection, which group A streptococcal (GAS) nature, were examined. Emm-types were determined by comparison ofemm gene sequenced part with data of CDC Streptococcus Laboratory. ASO and specific anti-group-carbohydrate IgM were measured with photometry and ELISA4 accordingly. Patient's personal data were analyzed by standard statistical programs. RESULTS: Among 34 emm-types of all streptococcal isolates emm28 and emm64 were registered only in invasive infection. Emm-types 1, 49, 60, 66, 77, 84, 88 were most often. Among 23 sera from invasive GAS-infection's patients, 15(65%) were ASO-negative, 6 (26%) were ASO-low-positive, and 2 (8%) were positive, but negative for the anti-group-A-carbohydrate IgM. CONCLUSION: Lower levels of the humoral immune response as well as risk factors such as trauma, alcoholism, diabetes, chronic venous insufficiency contributed to development of severe forms of GAS-infection. The main streptococcal emm-types for soft tissue's invasive GAS infection in one of Moscow surgical unit's patients in 2008-2011 were registered.

[Peculiarities of clinical and laboratory characteristics of the activity of streptococcal infection in the patients presenting with tonsillar pathology].

The objective of the present study was to characterize peculiar clinical and laboratory features of trivial tonsillitis for the substantiation of the necessity of prescription of antibacterial therapy. A total of 386 patients presenting with various forms of trivial tonsillitis were available for the determination of anti-streptococcal antibody (ASLO, anti-DN-ase B, ASPH) levels. The results of the measurement were compared based on the Centor scale generally used to estimate the necessity of prescribing antibacterial therapy for the treatment of sore throat. It is concluded that laboratory studies of characteristics of S. Рyogenes activity are needed in all the patients presenting with tonsillitis in order to elucidate the etiological factors responsible for pharyngalgia and the necessity of prescription of antibacterial therapy for the prevention of pyogenic systemic complications of streptococcal infection.

[Humoral immune response in patients with angina and soft tissue infections of group a streptococci etiology].

AIM: Evaluate informativity of simultaneous determination of antibodies (AB) against extracellular (AB against streptolysin-O-ASL-O) and cellular (IgM against A-polysaccharide - A-PSC) antigens in patients with angina and soft tissue infections caused by serogroup A streptococci (SGA) and identify features of humoral immune response to SGA infection according to infectious process localization. MATERIALS AND METHODS. 2 groups of patients with bacteriologically confirmed SGA infection (50 cases of angina - group 1 and 51 case of soft tissue infection - group 2) were examined for the presence of ASL-O by using Architect ci8200 analyzer (Abbott, USA) and IgM against SGA A-PSC by EIA. RESULTS. In group 1, 23 (46%) individuals were recognized as positive by ASL-O level, and in group 2 - 20 (39%; p>0.05); conditionally significant exceeding of normal values (more than 1.5 times) was detected in 25% of patients of each group. Increased level of antibodies against SGA A-PSC was detected in 43 (86%) patients of group 1, and in 30 (59%) of patients of group 2 (p<0.05). In group 1 exceeding of normal values of anti-A-PSC IgM was noted mostly by 1.5 +/- 0.5 times (74%). In group 2 in 43% of patients the level of anti-A-PSC IgM was above normal more than 2 times and in most cases in uncomplicated variants of disease course. In 45% of patients with severe form of soft tissue infection this parameter did not exceed normal values (p<0.05). CONCLUSION. In acute period of disease with simultaneous determination of ASL-O and IgM against A-PSC sensitivity of serologic diagnostics of SGA etiology angina and SGA infection of soft tissues was established to reach 92% and 72%, respectively, and humoral immune response to cellular AG in each form of SGA has its features.

[The prevalence and clinicoepidemiological characteristics of diseases caused by streptococcus group A in Russia].

AIM: to assess the significance of Streptococcus group A (SGA) infection in Moscow and the Russian Federation (RF). MATERIALS AND METHODS: The materials contained in the 1996-2007 annual official statistical records (forms Nos. 12, 14, 16-BH, C-51, of the State Committee for Statistics) were analyzed. RESULTS AND DISCUSSION: An average of 3.1 million (207.1 per 10,000 population) cases of SGA infection were annually notified in Russia. In the latter, the average annual rates of the incidence and prevalence of SGA infection (other than scarlet fever) in all age groups were much greater than those in Moscow. The average annual incidence of rheumatism was 5.1 and 6.0 per 10,000 in the RF and Moscow, respectively. The cases and days of temporary disability in Moscow were 2-3 times lower than those in the RF. The incidence and prevalence of other forms of SGA infection among the RF population significantly increased from 1 to 4%. In Moscow, there was a significant reduction in the incidence and prevalence of renal diseases, a decrease in the incidence of chronic rhinitis, nasopharyngitis, and sinusitis and in their prevalence. The prevalence of chronic tonsillitis, adenoiditis and paratonsillar abscesses tended to increase while their incidence showed no significant changes. CONCLUSION: Despite the significant declining trends for its incidence, prevalence, temporary disability, and mortality, SGA infection continues to cause a substantial socioeconomic damage and to remain to be one of the urgent public health problems of the country.