Polish journal of microbiology最新文献

The novel antibiotic ceftazidime-avibactam was introduced in Korea in 2023. This study evaluated the in vitro susceptibility of Pseudomonas aeruginosa isolates from a community-based hospital to various antibiotics, including ceftazidime-avibactam. A total of 100 non-duplicated consecutive P. aeruginosa isolates obtained from clinical specimens collected between October 2017 and March 2018 were analyzed. The minimum inhibitory concentrations (MICs) for ceftazidime, ceftazidime-avibactam, and colistin were determined by broth microdilution. Susceptibility to other antibiotics was assessed using the MicroScan system. Carbapenemase genes were detected by multiplex PCR. Among 100 isolates, 37% were multidrug-resistant (MDR), 27% were carbapenem-resistant (CR), and 9% were difficult-to-treat (DTR) P. aeruginosa. Colistin exhibited the highest efficacy against MDR and CR P. aeruginosa (MIC_50/90=1/4 mg/l, 89.2% and 88.9% susceptible), followed by ceftazidime-avibactam (MIC_50/90=4/16 mg/l, 86.5% and 85.2% susceptible). For DTR isolates, colistin (MIC_50/90=1/8 mg/l, 77.8% susceptible) was the most effective, followed by ceftazidime-avibactam (MIC_50/90= 4/≥128 mg/l, 66.7% susceptible). Carbapenemase genes were identified in four of 27 CR isolates (14.8%), including IMP- and KPC-type enzymes. Appropriate antibiotic use was observed in 71.4% of the non-MDR group and 56.8% of the MDR group. Clinical success was higher in the non-MDR group (85.7% vs. 64.9%, p=0.029), and P. aeruginosa infection was more frequently the cause of death in the MDR group (27% vs. 9.5%, p=0.043). P. aeruginosa isolated from a community-based hospital showed high antibiotic resistance, posing treatment challenges. Ceftazidime-avibactam may be a viable treatment option for MDR P. aeruginosa infections and warrants further clinical evaluation in Korea.

This non-interventional study was conducted at three cystic fibrosis (CF) treatment centers in Poland from August 2022 to July 2023. The aim was to assess the etiology of bacterial infection and evaluate antimicrobial susceptibility in CF patients. Prevalent pathogens were identified and their in vitro susceptibility to commonly prescribed antibiotics was assessed, highlighting potential needs in CF antibiotic therapy. Results indicated that Staphylococcus aureus was the most frequently isolated strain and was highly susceptible to tigecycline, linezolid, vancomycin, co-trimoxazole, and ceftaroline. Pseudomonas aeruginosa, the second most common strain, was susceptible to colistin, ceftazidime/avibactam, and tobramycin but exhibited high resistance to ciprofloxacin and cefepime. Coinfections of S. aureus and P. aeruginosa were notably more prevalent in adult CF patients. Although bacterial diversity was comparable between adults and children, limited sample sizes for specific species constrained the statistical analysis. Notably, comprehensive resistance data were lacking for most samples; however, many P. aeruginosa strains were classified as multidrug-resistant. Additionally, methicillin-resistant S. aureus and extended-spectrum β-lactamase-producing strains of Enterobacter cloacae and Klebsiella species were identified. This study highlights the importance of ongoing surveillance of bacterial pathogens and their resistance patterns in CF patients, as such information is essential for optimizing antibiotic therapy and improving clinical outcomes.

Legionella pneumophila is a common environmental bacterium that can cause severe respiratory disease. In this study, a reliable, rapid, and convenient detection method for L. pneumophila was established using a combination of recombinase polymerase amplification (RPA) and CRISPR/Cas12a technology. First, we designed three pairs of RPA primers and two types of crRNA based on the L. pneumophila-specific mip gene. Subsequently, we optimized the primers and amplification time for the RPA reaction, the crRNA for the CRISPR/Cas12a reaction, as well as the concentration of the fluorescent probe. We successfully constructed an RPA-CRISPR/Cas12a fluorescence detection system and a portable RPA-CRISPR/Cas12a LFB. The detection systems achieved a sensitivity of 5 copies/μl and high specificity. One hundred sixty environmental water samples tested by RPA-CRISPR/Cas12a LFB showed no significant difference compared to the qPCR method, providing a reliable tool for future on-site detection.

Streptomycetes synthesize a wide variety of biologically active compounds, such as antimicrobials, enzyme blockers, insecticides, and weed killers, offering the potential for use in farming as agents for enhancing plant health and defense. Streptomyces gossypiisoli TRM44567 was a novel strain isolated from continuously cropped cotton fields. An analysis of bioinformatics revealed that there are numerous natural product biosynthesis gene clusters with unknown functions in the genome sequence. Thirty-five potential natural product biosynthetic gene clusters were discovered from the genome of S. gossypiisoli TRM44567 by antiSMASH analysis. Furthermore, it was found that the strain TRM 44567 genome contained a cluster of tirandamycin biosynthetic gene cluster. Using the OSMAC strategy, screening revealed R5 medium was the most suitable medium. Based on modern isolation techniques, the fermentation product of strain TRM 44567 was identified as tirandamycin A and found to have inhibitory activity against Pseudomonas aeruginosa. The current research examines the genotypic traits of S. gossypiisoli TRM44567, suggesting its potential as a valuable reservoir of advantageous secondary compounds for medicinal and biotechnological uses.

The secondary metabolites produced by endophytic bacteria in lichens exhibit a wide range of bioactivities, including antibacterial, anti-inflammatory, and anti-tumor properties. In this study, 17 strains with distinct morphologies were isolated and identified from lichens collected in the Helan Mountains. Results show that the isolated strains included 13 Streptomyces strains, 1 Niallia strain, 1 Acinetobacter strain, 1 Peribacillus strain, and 1 Pseudarthrobacter strain. The antibacterial activity tests revealed that the secondary metabolites of 14 strains inhibited Staphylococcus aureus, 8 inhibited Proteus vulgaris, and 6 inhibited Candida albicans. In the salt and alkali resistance tests, three strains grew at NaCl concentrations of 25, 50, 75, and 100 g/l, respectively. Additionally, 14 strains exhibited robust alkali tolerance, growing at pH 8, 9, 10, and 11. These results highlight the remarkable biological and environmental adaptability of the strains isolated from lichens in the Helan Mountains, providing a solid foundation for subsequent exploration and research into novel structural compounds.

This study aimed to analyze the clinical features and infection status of COVID-19 patients with bacterial infections in Shaanxi Province. A retrospective analysis was conducted on 2,000 hospitalized patients from December 2022 to February 2023, categorized into mild, moderate, and severe COVID-19 groups. Among these, 300 patients had bacterial coinfections, with Klebsiella pneumoniae and Acinetobacter baumannii identified as the main pathogens. The study found a higher male prevalence and a higher median age, with severe cases mostly affecting individuals aged 70-90 years. The drug resistance rates of patients with mild and severe COVID-19 were low. Patients with severe COVID-19 were mainly infected with carbapenem-resistant Enterobacterales (CRE), carbapenem-resistant A. baumannii (CR-Ab) and extended-spectrum β-lactamase producing bacteria (ESBLs (+)). The findings highlight the importance of rational antibiotic use for severe COVID-19 patients to prevent the development of multidrug resistance caused by empirical medication and to provide a basis for clinical medication.

Glycosylation is one of the post-translational modifications that occur in the endoplasmic reticulum (ER)-Golgi pathway. During enzymatic glycosylation, glycosidic linkages form between saccharides, proteins and lipids. Cervicovaginal mucus (CVM), produced by epithelial cells in the female genital tract, is predominantly composed of water, mucins, and immunologically active factors. CVM is a viscoelastic natural hydrogel that lubricates the vagina and acts as a barrier against microorganisms. The glycan compounds of CVM function as cellular recognition, adherence and signaling molecules, as well as mediating host-microbe interactions. Additionally, the endocervical and vaginal epithelia secrete cervicovaginal fluid (CVF), which contains glycan compounds and various antimicrobial agents. The vaginal epithelium is mainly colonized by lactic acid bacteria (LAB) in a state of eubiosis. These bacteria produce immunomodulatory and antimicrobial compounds to prevent vaginitis. Disturbing vaginal eubiosis can lead to changes in the microbial community and the development of inflammation. Pathogens possess various mechanisms and virulence factors that facilitate their virulence. A significant proportion of microbial mechanisms and pathogen-host interactions are linked to glycan structural functions. Changes in the glycan profile are associated with vaginitis and may result from bacterial glycosidase activity, which compromises vaginal mucus and epithelial integrity. The aim of this review is to describe the glycan composition of CVF in eubiosis and dysbiosis, the influence of pathogens on glycan profiles, immune system regulation, and glycan-dependent factors in pathogen-host interactions. Understanding glycan-dependent events during vaginitis could be crucial for identifying new glycan biomarkers and treatment targets for vaginitis.

Monitoring antibiotic consumption (AMC) in the community sector is essential for understanding prescribing patterns and informing national stewardship policies. This analysis presents recent trends in community antibiotic use in Poland from 2019 to 2024, focusing on temporal dynamics and progress toward the European Union's 2030 reduction targets. By 2030, there should be an overall reduction in AMC, with at least 65% of total AMC in humans accounted for by drugs from the WHO Access group, first- or second-line antibiotics for common infections with a narrower spectrum of action. Data on systemic antibacterials (ATC J01) were obtained from IQVIA Poland and expressed in defined daily doses per 1,000 inhabitants per day (DID). Antibiotic use in the community sector sharply declined in 2020 due to the COVID-19 pandemic, but then increased, surpassing pre-pandemic levels by 2022. By 2024, community consumption reached 21.2 DID, remaining significantly above the EU/EEA average. Penicillins (J01C) consistently accounted for the largest share of use, primarily due to broad-spectrum agents like amoxicillin-beta-lactamase inhibitor combinations (e.g., amoxicillin-clavulanic acid). The use of narrow-spectrum penicillins remained low. Macrolides (J01F) and cephalosporins and other beta-lactams (J01D) experienced a marked post-pandemic increase, while tetracyclines (J01A) and quinolones (J01M) remained relatively stable. In 2024, Access antibiotics comprised 57.3% total outpatient use, indicating that narrower-spectrum agents are underused in Poland. Our findings suggest that enhancing stewardship programs, improving access to microbiological diagnostic testing, and ensuring consistent adherence to infection-prevention measures will be crucial in achieving the EU and WHO 2030 goals.

The increasing prevalence of oral fungal infections, particularly among denture wearers, underscores the need for accurate species identification. To investigate the prevalence and diversity of yeast species colonizing dentures. Oral swabs from denture surfaces were collected from 100 participants at the Peramerd Dental Center, Sulaymaniyah, Iraq, from September to November 2024. Samples were cultured on chromogenic media, and yeast isolates were identified and sequenced. Then, phylogenetic analysis was performed using the Neighbour-Joining method. Candida albicans was the most prevalent isolated species among patients with denatured samples (46%). However, 54% of isolates comprised other yeast species, including Kluyveromyces marxianus and Candida tropicalis (each at 8%), Nakaseomyces glabrata (6%), Meyerozyma guilliermondii (4%), Pichia kudriavzevii, and Candida dubliniensis (each at 2%). Notably, Pichia ethanolica, which is not typically considered part of the human mycobiome, was identified in two cases, including one instance of co-isolation with C. albicans. This study is the first to detect P. ethanolica on the denture surface used by the patients. Phylogenetic analysis confirmed species-level identity and genetic distinctiveness of both Candida and non-Candida isolates. These findings highlight the evolving diversity of oral mycobiota in denture wearers and the importance of molecular diagnostics in managing fungal infections. The high proportion of non-Candida species and the identification of P. ethanolica underscore the complex and potentially shifting fungal ecology associated with denture use, with implications for antifungal treatment strategies, and the need for further investigation into the origins and relevance of rare fungal species in the oral cavity.

Korea's unique climate and agricultural environment suggest that the gut microbiome of honey bees may possess distinctive compositions influenced by regional factors. With the decline in honey bee populations and rising health challenges, understanding the role of gut microbiomes is essential for enhancing honey bee health and their resilience to environmental stressors. To explore caste-specific gut microbiota and identify microbial signatures associated with honey bee health, this study examined the gut microbial composition of worker bees, queen bees, and drones of Apis mellifera using 16S rRNA gene amplicon sequencing. Analysis of beta diversity and species richness demonstrated significant differences between worker bees and both drones and queens, with no significant differences identified between drones and queens. Notably, Lactobacillus dominated all groups, comprising 98.6% of the drones, 95.4% of the queens, and 68.3% of the workers. Additionally, Bombella was prominent in queens (4%), whereas Gilliamella (23%) and Frischella (4.7%) were notably enriched in workers. Drones and queens exhibited similar gut microbiome profiles, while workers displayed distinctly different compositions. These findings underscore the variation in gut microbiota composition and potential functional roles across honey bee castes. Such microbial distinctions may reflect caste-specific roles and physiological demands within the colony. Future research should investigate the physiological roles of gut microbiota and their contributions to environmental resilience, paving the way for microbiome-based strategies to promote honey bee health. This study lays a crucial scientific foundation for conserving the honey bee ecosystem and promoting sustainable agriculture.