[Bacterial microbiota in exacerbation of chronic purulent otitis media in children]. / Bakterial'naya mikrobiota pri obostrenii khronicheskogo gnoinogo srednego otita u detei.

OBJECTIVE: To study current spectrum of bacterial pathogens that cause exacerbation of chronic suppurative otitis media (CSOM) in children, who live in Moscow region, and to investigate sensitivity of isolated strains to various antibacterial drugs. MATERIAL AND METHODS: The results of microbiome's bacterial cultivation of purulent discharge from tympanic cavities collected from 269 children with CSOM aged from 1.5 to 18 years for the period from 2017 to 2021 yr. were analyzed. The majority of examined subjects (70.6% from 190 children) had CSOM with cholesteatoma. RESULTS: Monoculture was received in 62.5% of examined patients, bacterial associations - in 25.7%, bacterial-fungal associations - in 2.6%, and there was no growth in 9.2% of subjects. Staphylococcus aureus, which was found in 36.1% of children, dominated among agents. Pseudomonas aeruginosa was the second most frequently diagnosed agent, revealed in 12.3% of patients. Candida spp. (7.1%) was prevalent in bacterial-fungal associations. The article presents the results of isolated strains' sensitivity to antibacterial drugs. The high resistance to oxacillin, cefoxitin and antipseudomonal drugs was found among strains collected from children with CSOM and cholesteatoma. CONCLUSION: S. aureus (36.1%) and P. aeruginosa (12.3%) remain the most common causative agents for exacerbation of chronic suppurative otitis media in children. Pathogenic fungi are not isolated separately, and Candida spp. (6.7%) dominates in bacterial-fungal associations. It is generally recognized and confirmed by our research, that topical fluoruquinolones (ciprofloxacin) are the most effective drugs for exacerbation of chronic suppurative otitis media treatment. Systemic antibiotics, of which fluoruquinolones (ciprofloxacin) are the most effective, are recommended in severe exacerbation, severe and destructive forms of chronic suppurative otitis media.

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.

[Features of bacterial microbiota in acute purulent otitis media in children]. / Osobennosti bakterial'noi mikrobioty pri ostrom gnoinom srednem otite u detei.

PURPOSE OF THE STUDY: The purpose is to study the spectrum of bacterial pathogens that cause acute purulent otitis media (APOM) in children of the Moscow region in modern conditions and assess their sensitivity to the main groups of antibiotics. MATERIAL AND METHODS: The study included 1.864 children who underwent examination and received treatment in the otorhinolaryngological department of Morozovskaya Pediatric Municipal Clinical Hospital in the period from 01 July 2018 to 31 June 2020 with a diagnosis of APOM. RESULTS: The study showed that the leading bacterial pathogens of APOM are Streptococcus pneumoniae (28.0%), Staphylococcus aureus (27.2%), Streptococcus pyogenes (22.2%), Haemophilus influenzae (7.8%), and Pseudomonas aeruginosa (6.5%). Attention is drawn to the increase in the level of resistance of S. pneumoniae to oxacillin (11.64%). CONCLUSIONS: The data obtained indicate the feasibility and prospects of vaccination against pneumococcal infection as one of the ways to curb the spread of resistance of S. pneumoniae to antibacterial drugs.

[The architectonics of microbe ecology in the purulent surgery department of municipal clinical hospital].

S. aureus, S. pyogenes, P. aerugenosa, E. coli, P mirabilis, A. baumannii, S. epidermidis, K. pneumoniae, E. faecalis, E. cloacae are the priority pathogens of various forms of pyoinflammatory diseases. They form the architectonics of microbe ecology of the purulent surgery department of multi-type hospital of regional level with S.aureus subsp.aureus playing dominating role. In case of unchanged specter of priority pathogens of pyoinflammatory and pyoseptic diseases the number of gram-positive coccuses decreases at the expense of decrease of number of streptococcuses and staphylococcuses. At the same time, the number of enterobacteria and gram-negative non-fermentative bacteria increases. The resistance ofgram-positive coccuses increases regarding erythromycin, clyndamicin and cyprofloxacin. The resistance of gram-negative bacilli increases regarding ciprofloxacin, cephalosporins of III-IV generations, amikacin. The resistance is the highest among clinical isolates MRSA, K. pneumoniae, A. baumannii. The vancomycin is active regarding all gram-positive pathogens. The carbapenems are active regarding all enterobacteriae. The carbapenems, cefoperazone/tazobactam, cefepime are most active regarding non-fermentative glucose oxidizing bacteria. The netimicin is active regarding A.baumannii. The polymyxine is active regarding P. aerugenosa. The circulation of S. aureus hospital strain of particular genotype is established confirming the propagation of epidemic S. aureus strains in Moscow multi-type medical institutions. The strains are genetically affined to epidemic strains in European and other countries according the international data base (http://SpaServer.ridom.de). The genetic typing of S. aureus ssp. aureus out-hospital hemocultures detected their considerable genetic variety. The epidemic relationship between isolates from different patients is not established. The algorithms of rationale antibacterial chemotherapy of pyoinflammatory and pyoseptic diseases are developed to be implemented in the purulent surgery department of municipal clinical hospital of Moscow.