Characteristics of Stenotrophomonas maltophilia isolates from cystic fibrosis patients in Russia.

Stenotrophomonas maltophilia is a common opportunistic microorganism and an important respiratory pathogen in cystic fibrosis (CF). The aim of this study was to determine antimicrobial resistance phenotypes, sequence-types (ST) and genetic determinants of antibiotic resistance in S. maltophilia strains recovered from CF patients in Russia. S. maltophilia isolates recovered from 170 CF patients were analyzed. Minimum inhibitory concentrations of antibacterial agents were determined using Sensititre Gram Negative GNX2F plates and the results were interpreted according to Clinical and Laboratory Standards Institute (CLSI) criteria. Whole-genome sequencing (WGS) was performed on MGISEQ-2000 platform. SPAdes software, Galaxy, ResFinder, Integrall and PubMLST were used for analysis of WGS data. S. maltophilia strains were identified from 24/170 (14%) CF patients. In total, 25 isolates were detected, two strains were isolated from the same patient. The isolates belonged to 17 different STs, including 5 new STs; ST4 was the most prevalent ST. Resistance to ceftazidime was observed in 60% of strains, to ticarcillin-clavulanate - in 32%, to levofloxacin - in 24%, to trimethoprim/sulfamethoxazole - in 12% of strains. All isolates were susceptible to minocycline. All ST4 isolates were resistant or intermediate to ceftazidime and ticarcillin-clavulanate. In two isolates, the sul1 gene was detected. In one isolate, sul1 was part of a class 1 integron. The detected integron also contained the blaGES-7 and aac(6')-Ib-cr genes. The ST4 sequence-type was the most prevalent ST among S. maltophilia strains recovered from CF patients in Russia. Antibiotic resistance genes, including sul1, blaGES-7, aac(6')-Ib-cr, were detected in single strains.

Genome features and antibiotic resistance of Pseudomonas aeruginosa strains isolated in patients with cystic fibrosis in the Russian Federation.

Cystic fibrosis (CF) is a common genetic disease, manifested by airway obstruction and chronic respiratory infection. The most prevalent infectious agent in airways of CF patients is Pseudomonas aeruginosa. This study aimed to determine sequence-types, antimicrobial resistance phenotypes and genes defining adaptive antibiotic resistance in P. aeruginosa isolates recovered from CF patients in Russia. In total, 84 P. aeruginosa strains from 64 CF patients were analyzed. Susceptibility to antibiotics was determined by disk diffusion test. Whole-genome sequencing (WGS) was performed on MGISEQ-2000 platform. SPAdes software, Galaxy, ResFinder, PubMLST were used for analysis of WGS data. Examined P. aeruginosa isolates belonged to 53 different sequence-types (STs), including 6 new STs. High-risk epidemic clone ST235 (10%) and clonal CF P. aeruginosa strains ST17, ST242, ST274 (7%) were detected. Non-susceptibility to ticarcillin-clavulanate, cefepime, imipenem was observed in 63%, 12% and 25% of isolates, respectively; to tobramycin - in 24%, to amikacin - in 35%; to ciprofloxacin, levofloxacin - in 35% and 57% of strains, respectively. Multidrug-resistant phenotype was detected in 18% of isolates. In examined strains, genes of beta-lactamases VIM-2 (5 ST235 strains), VEB-1 (two ST2592 strains), GES-1 (1 ST235 strain), PER-1 (1 ST235 strain) were found. Ciprofloxacin-modifying enzyme CrpP gene was detected in 67% of isolates, aminoglycoside-modifying enzymes AAD, ANT, AAC genes - in 7%, 4%, 12% of strains, respectively. P. aeruginosa isolates from CF patients in Russia demonstrate a high clonal diversity, which is similar to other P. aeruginosa infections. The isolates of high-risk clone and clonal CF P. aeruginosa strains are detected.

[PCR technique for prenatal diagnosis of fetal rhesus factor from peripheral maternal blood].

A procedure is proposed for the noninvasive determination of fetal rhesus factor in rhesus-negative pregnant women, which is based on the detection of the RHD gene in peripheral maternal blood by a PCR technique. The studies have shown the high sensitivity and specificity of determination of rhesus factor in a fetus at more than 15 weeks gestation. The technique does not require the use of such invasive and pregnancy-threatening procedures, as amniocentesis, cordocentesis or chorion biopsy. Furthermore, determination of fetal blood rhesus factor in rhesus-negative patients makes it possible to reduce expenses on the management of pregnancy, to avoid multiple determination of antibody rhesus and prevention of rhesus immunization, and to timely initiate therapeutic and preventive measures.

Olivopontocerebellar atrophy in a large Iakut kinship in eastern Siberia.

One-hundred cases of olivopontocerebellar atrophy, type 1, were found and studied in the Iakut population of Eastern Siberia. The disease followed a slowly progressive course of cerebellar insufficiency caused by degeneration in the cerebellar cortex, nuclei pontis, and inferior oliva. The disorder shows an autosomal dominant pattern of inheritance with a lower penetrance in females. The disease spread from a small region in the Aldan valley 200 to 300 years ago.

[Correlation of heredity and environmental factors in the etiology of Vilyui encephalomyelitis. II. A population genetic study in districts of Vilyui encephalomyelitis distribution]. / Sootnoshenie nasledstvennosti i sredovykh faktorov v étiologii viliuiskogo éntsefalomielita. Soobshchenie II. Populiatsionno-geneticheskoe issledovanie v raionakh rasprostraneniia viliuiskogo éntsefalomielita.

Population-genetic investigation was carried out in the regions endemic for Viljuisk encephalomyelitis (VE). The following indices were estimated: the relationship coefficient, the inbreeding coefficient, the intensity of migration, genetic structure of the population. The aim of the investigation was to explain causes of intrapopulational and, in some cases, of intragenus accumulation of the VE patients. No evidence of isolation or increased inbreeding were found in highly affected populations. The genetic structure of a group of VE patients tested for 9 polymorphic systems did not reveal any deviation from the control group. Several VE cases in healthy populations occured in some years after the immigration of a VE patient. These data confirm the hypothesis that VE is transmitted from a VE patient to healthy persons. Among these persons fall ill those who have a hereditary determined increased sensitivity to VE which results in intrapopulation and intragenus accumulation of VE cases.

[Correlation of heredity and environmental factors in the etiology of Vilyui encephalomyelitis. I. Patient frequency in families]. / Sootnoshenie nasledstvennosti i sredovykh faktorov v étiologii viliuiskogo éntsefalomielita. Soobshchenie I. Chastota bol'nykh v sem'iakh.

Viljuisk encephalomyelitis (VE) is a severe neurologic disease characterized by slow progressive dementia', oligobradykinesia, low spastic paraparesis and speech disturbances. It develops in persons of 20-50 years old. VE occurs in a small region of middle Viljui, but for last years the focus has considerably expanded. Etiology of VE is still obscure. 194 families with VE patients were examined. The data obtained contradict the hypothesis of simple recessive inheritance of VE. The value of the heredity coefficient, calculated on the basis of the Falconer - Edwards model, is 22-29% for relatives of the first relation degree. It suggests the existence of individual hereditary determined susceptibility to VE. 14 secondary cases were observed in affected families among adopted relatives (adopted children, husbands and wives of patients) with a rate exceeding random possible frequency. These observations have been evaluated as an evidence of horizontal transmission of the disease from patients with chronic forms to healthy persons. Obligatory condition for the transmission consists in a long-term contact (as a rule, more than one year). According to all known characteristics VE should be refferred to slow infections.