Background/objectivesBiologic extracellular matrix (ECM) implants are investigated for abdominal wall reconstruction because they may support tissue remodeling while limiting persistent foreign-body reactions. However, their response to contamination with multidrug-resistant pathogens remains insufficiently characterized. This exploratory study compared a bovine-derived peritoneum ECM scaffold with UltraPro mesh in a rat model of Acinetobacter baumannii contamination.MethodsThirty outbred rats were included. Twenty-four animals underwent ECM or UltraPro implantation and were evaluated on postoperative days 10 and 20 (n = 6 per subgroup); six non-implanted animals receiving sterile saline served as a non-implanted reference group. Abdominal wall defects were reconstructed and inoculated with 200 µL of an A. baumannii suspension at 109 CFU/mL. Tissue responses were assessed using semi-quantitative histological scoring based on ISO 10993-6 principles. Conventional microbiological culture was also performed.ResultsAll animals survived, and no clinically evident wound infection, dehiscence, or abscess formation was observed. On day 10, ECM demonstrated greater necrosis and polymorphonuclear-cell infiltration than UltraPro. By day 20, ECM showed reduced necrosis, increased cellular colonization, and greater reticulin fiber deposition, consistent with early tissue organization. UltraPro demonstrated increasing multinucleated giant-cell activity, fibrosis, granulomatous inflammation, and capsule formation. Conventional culture did not recover viable A. baumannii from ECM specimens, whereas the organism was recovered from 2 of 12 UltraPro specimens.ConclusionsUnder experimental A. baumannii contamination, ECM and UltraPro demonstrated distinct early patterns of tissue response. ECM showed a more pronounced acute inflammatory response followed by histological changes consistent with early tissue organization, whereas UltraPro demonstrated progressive foreign-body and fibrotic changes during the observation period. Because of the small subgroup size, short follow-up, absence of concurrent sterile implant controls, semi-quantitative histological assessment, and lack of quantitative microbiological and biomechanical evaluation, these findings should be considered exploratory and do not establish superior functional or clinical performance of either material. Longer-term microbiological, mechanical, and functional studies are required.

Background/Objectives: Klebsiella pneumoniae is a major Gram-negative pathogen associated with community-acquired pneumonia (CAP) and a critical contributor to antimicrobial resistance (AMR). Culture-based diagnostics remain the clinical standard but may underestimate microbial diversity and resistance gene profiles. This pilot study compared pathogen detection and antimicrobial resistance gene (ARG) repertoires in matched K. pneumoniae pure cultures and primary sputum samples using targeted next-generation sequencing (tNGS). Methods: We analyzed 153 sputum samples from patients with CAP. Among 48 culture-positive cases, 22 (14% overall; 54% culture-positive) yielded K. pneumoniae. MALDI-TOF MS, phenotypic drug susceptibility testing, and tNGS were conducted on both culture isolates and matched sputum specimens. Microbial composition, ARG diversity, and method concordance were evaluated, with focused analysis of discordant and fatal cases. Results: K. pneumoniae was detected in 14.4% of all CAP cases and accounted for 54.2% of culture-positive samples. Identification rates differed across methods: 35% by MALDI-TOF MS, 45% by culture tNGS, and 29% by sputum tNGS. Sputum tNGS revealed substantially higher microbial diversity than cultures (3.04 vs. 1.42 species per sample) and detected more than sixfold unique ARGs (38 vs. 7), including clinically relevant determinants that were absent from culture isolates. Concordance was high between MALDI-TOF MS and culture tNGS (κ = 0.712), but low between sputum and culture tNGS (κ = 0.279). Among twelve K. pneumoniae isolates included in AMR analysis, all showed resistance to β-lactams, and two-thirds exhibited MDR/XDR phenotypes. Genotypic screening identified seven ARGs, but major ESBL and carbapenemase genes were not detected, suggesting the presence of alternative resistance mechanisms. Overall, sputum tNGS provided additional etiological and resistome information not captured by cultivation and complemented classical diagnostics in CAP involving K. pneumoniae. Conclusions: Culture-based diagnostics and tNGS provide complementary insights into the detection and resistance profiling of K. pneumoniae in CAP, with sputum tNGS revealing broader microbial and resistome information than pure cultures, while classical methods remain essential for species confirmation and phenotypic AST. An integrated diagnostic approach combining both methodologies may improve pathogen detection, guide antimicrobial therapy, and enhance AMR surveillance in K. pneumoniae-associated CAP.

Background and Aims:Pneumonia is an inflammatory condition of the lower respiratory tract, commonly caused by infection and associated with substantial morbidity and healthcare utilization. The burden of pneumonia on healthcare is exacerbated by limited data on pathogenic causes and associated antimicrobial resistance (AMR). Here, we conducted a literature review and synthesized data on the microbial causes and AMR in hospitalized pneumonia patients from Kazakhstan. Methods:We searched PubMed, Medline, Embase, Web of Science, the Cochrane Central Register of Controlled Trials, eLIBRARY, and CyberLeninka for observational studies of hospitalized pneumonia patients reporting microbiologically confirmed pathogen and antimicrobial resistance data from Kazakhstan. Exclusion criteria were unclear pneumonia definitions or absence of pathogen-specific AMR data. We assessed study quality using the Joanna Briggs Institute checklist and extracted data on microbial prevalence and resistance rates by pathogen-antibiotic combinations. We synthesized microbial etiology and AMR patterns and performed random-effects meta-analysis of prevalence data. Results:Nine studies represented 1534 isolates from 1474 inpatients (2008-2022). The most prevalent pathogens were Streptococcus pneumoniae (17.8%), Streptococcus spp. (17.3%), Haemophilus influenzae (12.6%), and Klebsiella pneumoniae (10.7%). Hospital-acquired pathogens comprised 48% of isolates. Acinetobacter baumannii had the highest resistance, exceeding 70% across major antibiotic classes. Escherichia coli had high resistance to β-lactams (> 66%) and fluoroquinolones (63%). Pseudomonas aeruginosa had 60% fluoroquinolone and 27% carbapenem resistance. Fluoroquinolone resistance was widespread across multiple pathogens. K. pneumoniae had relatively lower resistance rates. Pathogen distribution varied by clinical setting and patient population. Conclusion:Data on the etiologic causes and AMR in pneumonia are sparse in Kazakhstan and methodologically heterogeneous. Hospital-acquired pneumonia pathogens were highly prevalent and associated with high AMR rates. These findings underscore the need for improved pathogen surveillance and antimicrobial stewardship in Kazakhstan to address the high burden of antibiotic-resistant and hospital-acquired pneumonia.

Background/Objectives: Implant-associated infections remain among the most severe and clinically challenging complications in contemporary orthopedics, largely due to the formation of persistent bacterial biofilms and the limited penetration of systemically administered antibiotics into the tissue-implant interface. In this context, local antibacterial functionalization of implantable materials represents a promising strategy for the prevention of early infectious complications. The objective of this study was to develop and comparatively evaluate the antimicrobial performance of PLA-based composites loaded with antibiotics from different pharmacological classes, with a view toward their potential application in individualized 3D-printed implants. Methods: Polylactic acid (PLA)-based composites incorporating gentamicin, ciprofloxacin, doxycycline, and vancomycin were fabricated using thermal processing under conditions compatible with extrusion and fused filament fabrication. Physicochemical characterization (FTIR, TGA, SEM) was performed to assess the structure and morphology of the composites, and in vitro antibiotic release studies were conducted. Antimicrobial activity was evaluated using an agar diffusion assay against ATCC reference strains and clinical isolates of methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MSSA and MRSA), Klebsiella pneumoniae, and Pseudomonas aeruginosa (n = 10 per species). The antibacterial performance of the composites was evaluated in comparison with standard commercial antibiotic disks used as qualitative reference controls. Results: Antibiotic-loaded PLA composites exhibited consistent and reproducible antibacterial activity, markedly exceeding that of neat PLA. The broadest activity spectrum was observed for PLA-ciprofloxacin (≈29-36 mm) and PLA-gentamicin (≈25-27 mm), which effectively inhibited both Gram-positive and Gram-negative clinical isolates, including MRSA and P. aeruginosa. PLA-vancomycin retained selective activity against staphylococci (≈14-15 mm), whereas PLA-doxycycline demonstrated limited efficacy against Gram-negative pathogens. Physicochemical analysis confirmed successful incorporation of antibiotics without detectable degradation of the polymer structure, while release studies demonstrated sustained antibiotic release from the composite materials. Importantly, the expected pharmacological activity profiles of the antibiotics were preserved after incorporation into the polymer matrix and subsequent high-temperature processing. Conclusions: The results demonstrate the feasibility of integrating clinically relevant antibiotics into a thermoplastic PLA matrix while preserving their selective antimicrobial activity following processing compatible with extrusion and additive manufacturing. The proposed PLA-based composites can be regarded as elements of a pharmacologically tunable antibacterial platform, offering a rationale for the development of context-dependent, biodegradable, 3D-printed implants for the local prevention of implant-associated infections in the setting of increasing antimicrobial resistance.

Background/Objectives: Staphylococcus aureus, particularly methicillin-resistant strains, is a leading cause of severe pneumonia. Understanding local molecular epidemiology, including virulence gene profiles and antimicrobial resistance (AMR) mechanisms, is crucial for effective infection control. This pilot study aimed to characterize S. aureus isolates from pneumonia patients in Karaganda, Kazakhstan. Methods: We collected 48 respiratory samples from patients with pneumonia across three medical institutions. Bacterial identification was performed using MALDI-TOF MS. Antimicrobial susceptibility testing (AST) was carried out using European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Whole-genome sequencing of S. aureus isolates was conducted on an Ion Torrent S5 platform. Genomic analysis included multilocus sequence typing (MLST), identification of virulence and AMR genes, and phylogenetic reconstruction. Results: S. aureus was identified in 14.6% (n = 7) of pneumonia cases included in this study. All isolates (100%, n = 7) were phenotypically resistant to benzylpenicillin. The mecA gene was detected in 57.1% of isolates (n = 4), while phenotypic resistance to methicillin was observed in 28.6% (n = 2) of the isolates. Resistance to azithromycin (57.1%, n = 4) and levofloxacin (42.9%, n = 3) was observed among the isolates. Two isolates (28.6%) were multidrug-resistant (MDR). Genomic analysis revealed the prevalence of the ST22 clone (57.1%, n = 4) in the studied cohort. Other sequence types were ST97, ST8, and ST45 (14.3% each). Phylogenetic analysis showed clustering consistent with MLST profiles. All isolates carried a conserved core virulence arsenal, including hemolysin (hla, hlg), biofilm-forming genes (icaADBC), immune evasion genes (sak, scn), and iron acquisition genes (isd). The Panton-Valentine leukocidin (PVL) genes were detected in three isolates. AMR gene analysis revealed the ubiquitous presence of mepA and tetracycline efflux pump genes, along with regulatory genes (arlRS, mepR, mgrA). The blaZ and ermA genes were not detected despite high phenotypic resistance to penicillin and macrolides. Conclusions: This study reports the identification of the virulent and resistant ST22 S. aureus clone in pneumonia cases in Karaganda, Kazakhstan. The discordance between phenotypic and genotypic AMR profiles underscores the necessity for integrated diagnostic approaches.

This study presents the results of analyzing the sputum microbiome of 46 patients diagnosed with pneumonia using targeted NGS sequencing of the 16S rRNA gene. As a result of the study, 114 species of bacteria belonging to 47 genera and 29 families were identified. Based on the obtained data, potential pathogens associated with the development of pneumonia were identified, and a quantitative analysis of their prevalence among patients was conducted. At the species level, Streptococcus pneumoniae was detected in 26 samples (56.5%). Acinetobacter baumannii was found in 10 samples (21.7%). Klebsiella pneumoniae was detected in 9 samples (19.5%), and Pseudomonas aeruginosa was found in 17.4% of samples. Other species that may be involved in the development of pneumonia included Escherichia coli, Haemophilus influenzae, and Staphylococcus aureus in 15.2%, 10.87%, and 8.7% of samples, respectively. Additionally, Neisseria meningitidis was detected in 5 samples (10.8%), and Stenotrophomonas maltophilia was found in two samples. The obtained results can contribute to a deeper understanding of microbiome communities associated with pneumonia and enrich knowledge about the microbiome of the upper respiratory tract. These data may be useful for developing new strategies for the diagnosis and treatment of pneumonia, as well as for optimizing preventive measures.

Aim: The purpose of this study was to evaluate sub-species typing by matrix-activated laser desorption/ionisation mass spectrometry on the example of Klebsiella pneumoniae isolated from patients with pulmonary tuberculosis in Karaganda region. Materials and Methods: This study evaluated the potential of MALDI-TOF MS for epidemiological identification of Klebsiella pneumoniae isolated from pulmonary tuberculosis patients in Karaganda region. A total of 47 strains of Klebsiella pneumoniae obtained between 2015 and 2019 were typed. Mass spectra were taken using Microflex LT MALDI-TOF (Bruker) according to standard procedure. Results: As a result, MALDI-TOF evaluation of subspecies typing on the example of Klebsiella pneumoniae isolated from patients with pulmonary tuberculosis in Karaganda region, predominantly showed the diversity of isolates, indicating their out-of-hospital nature. Based on all available information, including facts, sources, and experimental results, it can be reasonably concluded that the current study of Klebsiella pneumoniae does not provide a complete picture of the epidemiology of this microorganism. Conclusions: The current study provided a limited opportunity to investigate the genetic structure and diversity of Klebsiella pneumoniae subspecies more accurately. The findings suggest that the time-of-flight laser-ionisation ablation mass spectrometry method with magnetic focusing is more likely to detect differences in external characteristics between individual specimens of the same species than internal genetic variation in the microorganisms under study. The practical relevance of this study is to inform the development of more effective infection control strategies in clinical practice and infection control.

ABSTRACTHelicobacter pylori (H. pylori) infection can cause a wide range of gastrointestinal disorders, including chronic nonatrophic gastritis, multifocal atrophic gastritis, peptic ulcer disease, gastric adenocarcinoma, and extra‐nodal B‐cell lymphoma. Although the prevalence of H. pylori infection has decreased among adults, it is still very common. Approximately 90% of gastric adenocarcinomas are associated with H. pylori infection. Despite the established link between H. pylori infection and noncardiac gastric cancer, and the increasing incidence of gastric cancer in Kazakhstan, there are limited data on the prevalence of H. pylori in the country. This may be due to the difficulty of detecting H. pylori and the unavailability of diagnostic methods. This review presents the current data of diagnostic tests for the detection of H. pylori in Kazakhstan with a focus on limitations and practical significance.

BACKGROUND:To better understand the factors associated with Helicobacter pylori infection, it is important to quantify the prevalence of H. pylori and identify the clinical and demographic characteristics of individuals with the infection. METHOD:In this cross-sectional study 369 participants underwent a structured questionnaire, urease breath test, and endoscopy to determine their H. pylori status. RESULTS:The frequency of H. pylori in the sample was 27.64%, and erosive antral gastritis, gastric ulcers, and duodenal ulcers were found to be significantly associated with infection. However, no differences were found in social status, family size, or shared utensil use between individuals with and without the infection. CONCLUSION:These findings suggest that H. pylori is a significant risk factor for gastrointestinal conditions.

Background/Objectives: Acinetobacter baumannii is an increasingly significant nosocomial pathogen causing severe infections globally. The emergence of multidrug-resistant A. baumannii strains has raised concerns about the efficacy of current treatment options. This study aimed to investigate the molecular epidemiology and antimicrobial resistance patterns of A. baumannii isolates from Kazakhstan. Methods: We collected nine A. baumannii isolates in 2022–2023 in Karaganda, Kazakhstan, which were then subjected to whole-genome sequencing (WGS) using the IonTorrent platform for genome characterization. Multilocus sequence typing (MLST) was used to classify the isolates into distinct clonal complexes. In addition, antibiotic susceptibility testing was conducted using the standard methods for a range of antibiotics commonly used against A. baumannii. Results: Our results revealed a high degree of genomic diversity among isolates from Kazakhstan, with multiple distinct classes identified: ST78 (n = 4, 44.4%), ST15 (n = 2, 22.2%), ST2 (n = 2, 22.2%), and ST193 (n = 1, 11%). MLST analysis showed that ST78Pas/1104Oxf (harboring blaOXA-72 and blaOXA-90 genes) were prevalent among the multidrug-resistant isolates. Based on the results of MLST, KL, and OCL, the analyzed isolates were assigned to specific international clones: IC2—ST2(Pas)-KL2/168-OCL1, IC4—ST15(Pas)-KL9-OCL7, and IC6—ST78(Pas)-KL49-OCL1. Notably, these isolates exhibited resistance to multiple antibiotics including meropenem, imipenem, gentamicin, amikacin, and ciprofloxacin. Conclusions: This study highlighted the complex molecular epidemiology of A. baumannii in Kazakhstan over a two-year period, underscoring the need for targeted surveillance strategies to monitor antimicrobial resistance patterns. The emergence and dissemination of multidrug-resistant strains within this timeframe emphasizes the importance of whole-genome sequencing as a diagnostic tool and underscores the challenges posed by these infections.

Helicobacter pylori, also known as H. pylori, is a global health concern, especially in countries with high rates of stomach cancer. Eliminating this bacterium effectively is crucial for preventing and treating related gastrointestinal conditions. Unfortunately, antibiotic resistance makes it difficult to successfully treat H. pylori infections. This review will focus on antibiotic resistance in H. pylori populations in Central Asia, as information about this issue in this region is limited.

Helicobacter pylori (H. pylori) is a global health concern, particularly in regions with a high incidence of stomach cancer. The effective eradication of this bacteria is essential for the prevention and treatment of related gastrointestinal disorders. However, antibiotic resistance has emerged as a significant challenge to effective treatment. This review examines antibiotic resistance among H. pylori populations in Central Asia, a region with limited data on this topic. We critically analyze the available literature, exploring the mechanisms behind resistance and highlighting implications for clinical practice and future research. Despite the lack of studies in the region, data suggest alarming levels of resistance to two common antibiotics, clarithromycin and metronidazole. These results underscore the need for enhanced surveillance and personalized treatment strategies to combat H. pylori infections and reduce the risk of stomach cancer in Central Asian populations. Hope to be useful for diagnosis. Also medical management is important for future trends. Youth age are also in attention.

Objectives: The widespread distribution of SARS-CoV-2 and its high contagiousness pose a challenge for researchers seeking to develop a rapid and cost-effective screening method to identify carriers of this virus. RT-PCR is considered the gold standard for detecting viral RNA in nasopharyngeal swabs, but it is time-consuming and requires constant changes in the primer composition due to the mutation of SARS-CoV-2 strains. We propose a method for the detection of SARS-CoV-2 in nasopharyngeal swabs using MALDI-TOF MS and machine learning. Methods: Nasopharyngeal swabs from patients with PCR-confirmed COVID-19 and control participants were tested (130 and 80 swabs, respectively) with MALDI-TOF MS MicroFlex LT using the HCCA matrix. MALDI spectra were preprocessed in R version 4.1.2 software with the MALDIquant R package using the workflow: sqrt transformation, wavelet smoothing, SNIP-based base removal, and PQN intensity calibration. Peaks were detected with MAD algorithms with following Peak alignment on the following parameters: minFreq 70% and tolerance 0.005. Machine learning was performed with the rtemis r package on GLM, random forest, and XGBoost models. Results: These models were characterized by specificity, sensitivity, and F1 score. GLM models (specificity 1 and sensitivity 0.5) showed a low F1 score of 0.71. However, the random forest and XGBoost models demonstrated sensitivity, specificity, and F1 score equaling 1. Conclusions: We propose a screening method for SARS-CoV-2 detection (sensitivity 1 and specificity 1). This methodology combines the analysis of nasopharyngeal swab samples using MALDI-TOF-MS with machine learning. It is suitable for screening patients with COVID-19 at the first stages of diagnosis. Random forest and XGBoost models demonstrated sensitivity, specificity, and F1 scores equaling 1.

Objectives: To determine virulence genes and sensitivity to antibacterial drugs of Staphylococcus epidermidis isolated from blood cultures of newborns. Methods: A study of сoagulase-negative Staphylococcus (CoNS) from newborns with sepsis was conducted in the regional perinatal center in Karaganda, Kazakhstan. Blood-culture identification was performed using MALDI-TOF MS. Virulence factors were determined on primers ( sdrG , sdrG , atl , lip , nuc , ebh , hlb , sspA , sspB , and gehD ) with PCR (Bio-Rad CFX 96). Susceptibility to antibiotics determination was carried out using the disc-diffusion method. Testing with cefoxitin was used to detect methicillin resistance in staphylococci. Results: Overall, 18 Staphylococcus epidermidis isolates from blood cultures of newborns with sepsis were investigated from January to December 2021. The frequency of detection of virulence genes was distributed as follows: atl (94.5%), sspB (94.5%), sspA (89%), gehD (89%), ebh (89%), hlb (72%), sdrG (39%), sdrF (28%), nuc (28%), and lip (13%). Also, 10 isolates (55%) were resistant to cefoxitin (MRSE). Furthermore, 72% of S. epidermidis isolates showed resistance to azithromycin and 33% were resistant to clindamycin and gentamicin. Also, 39% of strains were resistant to fluorchinolones. All isolates were susceptible to vancomycin, linezolid, and fusidic acid. Conclusions: S. epidermidis strains isolated from blood cultures had high rates of exoenzymes sspB, sspA, gehD, autolysin (atl), β-hemolysin (hlb), and cell-wall–associated fibronectin-binding protein (ebh). Among 18 neonatal sepsis pathogens, 10 (55%) were MRSE, so it is necessary to pay attention to antibiotic therapy adjustment.

Background: Acinetobacter species other than A. baumannii are becoming increasingly more important as opportunistic pathogens for humans. The primary aim of this study was to assess the prevalence, species distribution, antimicrobial resistance patterns, and carbapenemase gene content of clinical Acinetobacter non-baumannii (Anb) isolates that were collected as part of a sentinel surveillance program of bacterial infections in hospitalized patients. The secondary aim was to evaluate the performance of MALDI-TOF MS systems for the species-level identification of Anb isolates. Methods: Clinical bacterial isolates were collected from multiple sites across Russia and Kazakhstan in 2016–2022. Species identification was performed by means of MALDI-TOF MS, with the Autobio and Bruker systems used in parallel. The PCR detection of the species-specific blaOXA-51-like gene was used as a means of differentiating A. baumannii from Anb species, and the partial sequencing of the rpoB gene was used as a reference method for Anb species identification. The susceptibility of isolates to antibiotics (amikacin, cefepime, ciprofloxacin, colistin, gentamicin, imipenem, meropenem, sulbactam, tigecycline, tobramycin, and trimethoprim–sulfamethoxazole) was determined using the broth microdilution method. The presence of the most common in Acinetobacter-acquired carbapenemase genes (blaOXA-23-like, blaOXA-24/40-like, blaOXA-58-like, blaNDM, blaIMP, and blaVIM) was assessed using real-time PCR. Results: In total, 234 isolates were identified as belonging to 14 Anb species. These comprised 6.2% of Acinetobacter spp. and 0.7% of all bacterial isolates from the observations. Among the Anb species, the most abundant were A. pittii (42.7%), A. nosocomialis (13.7%), the A. calcoaceticus/oleivorans group (9.0%), A. bereziniae (7.7%), and A. geminorum (6.0%). Notably, two environmental species, A. oleivorans and A. courvalinii, were found for the first time in the clinical samples of patients with urinary tract infections. The prevalence of resistance to different antibiotics in Anb species varied from <4% (meropenem and colistin) to 11.2% (gentamicin). Most isolates were susceptible to all antibiotics; however, sporadic isolates of A. bereziniae, A. johnsonii, A. nosocomialis, A. oleivorans, A. pittii, and A. ursingii were resistant to carbapenems. A. bereziniae was more frequently resistant to sulbactam, aminoglycosides, trimethoprim–sulfamethoxazole, and tigecycline than the other species. Four (1.7%) isolates of A. bereziniae, A. johnsonii, A. pittii were found to carry carbapenemase genes (blaOXA-58-like and blaNDM, either alone or in combination). The overall accuracy rates of the species-level identification of Anb isolates with the Autobio and Bruker systems were 80.8% and 88.5%, with misidentifications occurring in 5 and 3 species, respectively. Conclusions: This study provides important new insights into the methods of identification, occurrence, species distribution, and antibiotic resistance traits of clinical Anb isolates.

Our study was carried out to characterize respiratory tract microbiota in patients with “COVID-like pneumonia” in Kazakhstan and analyze differences between COVID-19 positive and negative groups. Sputum samples were collected from hospitalized patients, ≥18 years old, in the three cities in Kazakhstan with the highest COVID-19 burden in July 2020. Isolates were identified by MALDI-TOF MS. Susceptibility testing was performed by disk diffusion. We used SPSS 26 and MedCalc 19 for statistical analysis. Among 209 patients with pneumonia, the median age was 62 years and 55% were male. RT-PCR-confirmed SARS-CoV-2 cases were found in 40% of patients, and 46% had a bacterial co-infection. Co-infection was not associated with SARS-CoV-2 RT-PCR test results, but antibiotic use was. The most frequent bacteria were Klebsiella pneumoniae (23%), Escherichia coli (12%), and Acinetobacter baumannii (11%). Notably, 68% of Klebsiella pneumoniae had phenotypic evidence of extended-spectrum beta-lactamases in disk diffusion assays, 87% of Acinetobacter baumannii exhibited resistance to beta-lactams, and >50% of E. coli strains had evidence of ESBL production and 64% were resistant to fluoroquinolones. Patients with a bacterial co-infection had a higher proportion of severe disease than those without a co-infection. The results reinforce the importance of using appropriate targeted antibiotics and effective infection control practices to prevent the spread of resistant nosocomial infections.

Topic: 30. Infections in hematology (incl. supportive care/therapy) Background: Antimicrobial resistance (AMR) which is a serious health problem worldwide is of particular importance in hematology. Patients receiving intensive chemotherapy have an increased risk of febrile episodes due to the development of neutropenia. The COVID-19 pandemic has exacerbated the problem of AMR, which was largely caused by the improper use of antibiotics. Monitoring of antibiotic resistance and its consequences in the post COVID period is crucial for assessing and optimizing infectious safety in hematology hospitals. Aims: The aim of the study was to study the dynamics of antibiotic-resistant strains and the outcomes of therapy in patients with bloodstream infections in the post COVID period. Methods: A retrospective analysis of the structure and antibiotic resistance of 91 pathogens obtained from the blood of 67 patients being treated at the hematology center of Karaganda in the period from 2021 to 2022 was carried out. The average age of patients was 57.47 years±15.9 years, patients with acute leukemia prevailed - 29 people, 72.4% of them with AML; chronic lymphoproliferative diseases - 20, 50% of them with multiple myeloma, MDS-7, CMP-3, blood diseases - 8 people. The total number of episodes of febrile fever is 91, of which febrile neutropenia is in 46 cases. Bacteriological examination was carried out with identification by time-of-flight mass spectrometry, determination of antimicrobial sensitivity was carried out in accordance with the recommendations of CLSI M100-24. The structure of the 1st line of antibacterial therapy and its effectiveness were analyzed. The outcomes were cases of positive treatment of febrile fever, deaths within 28 days, the need for 2 or more courses of antibacterial therapy. Statistical analysis was carried out using SPSS version 23.0. Results: Analysis of the structure of pathogens that were isolated from the blood showed that in 2022 the proportion of gram-negative bacteria increased from 26.9% to 47.7%. The incidence of Escherichia coli decreased from 57.1% to 16.1% due to the appearance of non-fermenting microorganisms in the etiological structure of blood diseases, such as Pseudomonas aeruginosa (22.6%), Stenotrophomonas maltophilia (9.67%), the incidence of Klebsiella pneumoniae remained unchanged at 28.5-32.2%. The prevalence of the specific gravity of staphylococci remained - 83.3-83.8%, the level of MRSA positive staphylococci was 0-13.3%. The analysis showed an increase in antibiotic-resistant forms among gram-negative bacteria from 0% in 2021 to 53.1% in 2022: of these, 34.4% are ESBL-resistant forms, 15.6% are CRK/4MRGN and 3.12% are CRK. In the structure of line 1 antibacterial therapy in 2021, ceftazidime and piperacillin tazobactam occupied the same proportion - 44.4% each, in 2022 - the appointment of piperacillin tazobactam increased to 76.6%. The frequency of achieving a positive effect of therapy in 2021 and 2022 did not differ - 66.7% and 64.0%, respectively (χ2=1.28; p=0.258), however, the frequency of prescribing 2 or more courses of antibacterial therapy in 2022 was significantly higher compared to 2021 - 62.5% and 25.9% ((χ2=10.45; p=0.002). Summary/Conclusion: The growth of antibiotic-resistant gram-negative non-fermenting strains in hematological hospitals is accompanied by a deterioration in the results of line 1 therapy, additional consumption of broad-spectrum antibacterial drugs. There is an increasing need to monitor the causes of infection and establish their own empirical protocols of antibacterial therapy to achieve the best results in the treatment of febrile neutropenia. Keywords: Multidrug resistance, Febrile neutropenia, Infection

Aim: To study the role of E. coli intestinal translocation in the development of acute obstructive pyelonephritis in an experiment. Material and methods: An experimental study was conducted on 60 male rabbits weighing 3000±500 g. The animals were divided into 3 groups of 20 animals each: experimental, control and intermediate control group. The acute obstructive pyelonephritis with the ureter blocking by laparotomy and introduction of the strain into the intestine were simulated in the animals of the experimental group. In the control group, the model was performed anologically as in the experimental group, but without the ureter blocking. In the intermediate control group, laparotomy was performed, the ureter was isolated without blocking and without the introduction of a bacterial strain. 10 animals of each group were removed from the experiment on the 3rd and 5th days, kidney tissue and urine were intake. As a reference marker strain, the laboratory strain E. coli No. 49579 was used, which was obtained from a patient with a urological infection and had resistance to cefepime, ciprofloxacin and tetracycline. Biomaterials were studied by microbiological examination and subspecific typing of strains using the MALDI-TOF MS method, antibiotic sensitivity was determined. Results: E. coli strain was isolated in all animals of the experimental group and in 2 animals of the control group on the 5th day. During subspecific typing by the MALDI-TOF MS method, the isolated strains were identical in ribosomal proteins, and also had the same sensitivity to the said antibiotics. When analyzing the amount of lg CFU E.coli in urine after the experiment between the experimental and control group, we found that, on day 3, there were statistically significant differences between the groups (p=0.005), and on day 5, the amount of lg CFU E.coli was 13 times greater (p=0.004).A comparative analysis of the lg CFU E.coli index in kidney tissue on 3 (p=0.004) and 5 (p=0.003) days revealed statistically significant differences between the experimental group and the control group. Conclusion: The results of identification and subspecific typing of isolated microorganisms confirmed that the strains isolated from the urinary tract were identical to the reference strain introduced into the gastrointestinal tract during the experiment, which confirms the role of translocation of intestinal microorganisms in the development of acute obstructive pyelonephritis.

The upper urinary tract stenting allows to restore the ureteral patency in various situations. However, one of the main disadvantages of stenting is bacterial contamination, which can be a source of persistent infections that hardly respond to antibiotic therapy. The aim of this study was to investigate the local spectrum of bacterial pathogens and their susceptibility to antibiotics in order to optimize antibacterial therapy after upper urinary tract stenting. A prospective observational study was conducted in which 140 urine samples were examined (70 before stenting and 70 after stenting). Bacterial growth was detected in 37 patients (52.8%) before stenting and in 43 patients (61.4%) after stenting. E. coli (13 (28.8%)) and Streptococcus spp. (8 (17.6%)) strains were more commonly detected before stenting; P. aeruginosa (15 (31.2%)) and E. coli (8 (16.6%)) were usually revealed after stenting. The proportion of P. aeruginosa strains after stenting grew from 4.4% up to 31.2%. E. coli strains were resistant to ampicillin (92.3% before and 100% after stenting). Three strains of E. coli (23.1%) and six strains of P. aeruginosa (40%) were multidrug-resistant. Determination of the bacterial sensitivity to antibiotics and identification of antibiotic-resistant forms of bacteria is a factor in reducing the risk of complications and optimizing antibiotic therapy during the upper urinary tract stenting.