Acta microbiologica et immunologica Hungarica最新文献

Aerococcus urinae is an uncommon uropathogen that mainly affect the elderly with predisposing conditions. Aim of the present study was to investigate the clinical and microbiological characteristics of patients with urinary tract infections (UTIs) by A. urinae and determine the antimicrobial susceptibility patterns of the isolates, over the last 3 years at our institution. The medical records and microbiological data of patients from whom A. urinae was isolated from urine cultures at the university hospital of Heraklion, Crete, Greece, between 2020 and 2022, were retrospectively analyzed. The isolates were identified by the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Susceptibilities for antimicrobial agents were determined by the disk diffusion method and results were interpreted using the 2024 EUCAST breakpoints. The minimum inhibitory concentration for fosfomycin was evaluated by the MIC Test Strip method. A. urinae was encountered in cultures of 24 patients. The median patient's age was 72 years, and females slightly outnumbered males. Underlying diseases such as urologic disease, chronic lung disease, chronic kidney disease, heart disease, diabetes mellitus and dementia were found in 79.2% of patients. Two of the patients did not meet the criteria for a UTI. Susceptibility rates to penicillin, amoxicillin, meropenem, ciprofloxacin, levofloxacin, rifampicin, vancomycin, nitrofurantoin and fosfomycin were 100%, 100%, 100%, 83.3%, 79.2%, 100%, 100%, 95.8%, and 91.7%, respectively. Further surveillance studies and clinical trials are needed to confirm our data and to investigate the in vivo efficacy of the antimicrobial agents to treat UTIs by A. urinae.

The incidence of lower respiratory tract infections (LRTIs) caused by multidrug-resistant organisms (MDRO) has been high in recent years. However, traditional etiological detection methods have not been able to meet the needs for clinical diagnosis and prognosis of LRTIs. The rapid development of metagenomic next-generation sequencing (mNGS) provides new insights for diagnosis and treatment of LRTIs. We conducted a retrospective study on 95 patients with lower respiratory tract infections caused by MDRO admitted to our respiratory department from January 2022 to December 2023. These patients underwent mNGS testing and conventional culture testing. Additionally, 150 patients without lower respiratory tract infections caused by MDRO during the same period were included as the non-MDRO group. General information was collected, and Logistic regression analysis was performed to identify risk factors for MDRO infections in patients with lower respiratory tract infections. Our results show that the time to pathogen detection by mNGS was 50.76 ± 1.730 h, that is significantly shorter than 55.53 ± 2.782 h required for conventional culture testing. The pathogen detection rate by mNGS was 89.47% (85/95), higher than the 67.37% (64/95) identified by conventional testing. In terms of pathogen genus distribution, mNGS detected a total of 279 pathogens, while conventional testing detected 121 pathogens. Logistic multivariate regression analysis identified that the use of more than two antibiotics, invasive procedures, invasive mechanical ventilation for ≥7 days, and stay in the respiratory intensive care unit (RICU) for ≥7 days were the main influencing factors for lower respiratory tract infections caused by MDRO (P < 0.05).

Klebsiella pneumoniae is a major pathogen associated with hospital-acquired infections, particularly those involving multidrug-resistant strains. Carbapenem resistance, often driven by carbapenemases such as KPC, VIM, OXA-48, and NDM, poses a significant challenge in clinical settings. This study reports on K. pneumoniae strain A165, isolated from a blood culture of a 51-year-old female patient hospitalized for respiratory distress post-SARS-CoV-2 infection. This K. pneumoniae strain exhibited resistance to several antibiotics, including carbapenems, cephalosporins, aminoglycosides, and fluoroquinolones, but remained susceptible to gentamicin, colistin, and trimethoprim-sulfamethoxazole. Next-generation sequencing was performed on Ion torrent platform, that revealed a genome size of 5,676,404 bp, including a chromosome and six plasmids. The strain was classified as sequence type 11 (ST11), a high-risk lineage associated with carbapenem resistance. The resistome of A165 included multiple β-lactamase genes, such as blaNDM-1 and blaOXA-48, as well as genes conferring resistance to other antibiotic classes. The virulome analysis identified genes involved in iron acquisition (yersiniabactin operon genes: ybtE, ybtT, irp1, irp2; aerobactin receptor: iutA), adhesion (mrkA-J, fimA-K), capsule and biofilm formation (rcsA, rcsB, ompA) and resistance to complement (traT) contributing to its pathogenic potential. The mobilome analysis revealed nine insertion sequences, including ISKpn1, ISKpn18, ISKpn43, ISKpn28, ISKpn14, ISEcp1, and IS6100. The strain also harbored six replicons: Col440II, ColRNAI, IncFIA(HI1), IncFIB(K), IncFII(K), and IncR, which are associated with the horizontal transfer of resistance and virulence genes. Comparative analysis with global isolates demonstrated the widespread dissemination of carbapenemase-producing K. pneumoniae, with notable occurrences in Europe, Asia, and the Americas. This study highlights the growing concern of multidrug-resistant K. pneumoniae in hospital settings and emphasizes the need for robust surveillance and infection control measures.

Shigellosis, a diarrheal disease caused by Shigella species, is a significant public health concern, particularly in developing countries with inadequate sanitation systems. This study aimed to investigate the patterns of antibiotic resistance, ESBL and AmpC genes, integrons, and enterotoxin genes in Shigella species isolated from patients with gastroenteritis in Northeast Iran. This cross-sectional study was conducted between January 2017 and December 2019 at a tertiary care hospital in Northeast Iran. A total of 110 Shigella isolates were collected from stool samples of patients with gastroenteritis. The isolates were identified using conventional biochemical tests and confirmed by PCR. The highest resistance rates were detected for ampicillin (88.2%) and cotrimoxazole (84.5%). Altogether 64.5% of isolates exhibited multidrug resistance however, ESBL and AmpC phenotypes were detected in 34.54% and 1.81% of isolates, respectively. Interestingly, blaCTX-M-15 and blaTEM were detected in all ESBL-positive isolates but integron class 1, 2, and 3 were identified in 97.3%, 76.4%, and 59.1% of isolates, respectively. The sen gene was present in 72.7% of the isolates. In this study CTX-M-15 production was detected in 31 strains of Shigella sonnei and in 7 strains of Shigella flexneri. The high prevalence of multidrug-resistant Shigella isolates is concerning and shows the need for continuous monitoring and rational use of antibiotics.

This study investigated a strain of Klebsiella pneumoniae, identified as GRTHES, which exhibited extensive antibiotic resistance. The strain was resistant to all beta-lactams, including combinations with newer agents such as meropenem/vaborbactam and imipenem/relebactam, as well as to aminoglycosides, fluoroquinolones, fosfomycin, trimethoprim-sulfamethoxazole and colistin. It remained susceptible to tigecycline. Whole-genome sequencing was performed by Ion Torrent platform on the K. pneumoniae strain. Genomic analysis revealed a genome length of 5,808,650 bp and a GC content of 56.9%. Advanced sequencing techniques and bioinformatic tools were used to assess resistance genes and plasmid replicons, highlighting the emergence of multidrug resistance and virulence traits. The strain carried blaNDM-1 and blaKPC-3 genes and was designated to KL107 O2afg type. Colistin resistance-associated mgrB/pmrB gene mutations were present, and the strain also harbored yersiniabactin-encoding ybt gene. Our findings provide insights into the genomic context of blaNDM-1 and blaKPC-3 carbapenemase-producing K. pneumoniae and emphasize the importance of continuous surveillance and novel therapeutic strategies to combat multidrug-resistant bacterial infections. It is the first time that an NDM-1 and KPC-3 co-producing strain of K. pneumoniae ST512 is identified in Greece. This study highlights the essential role of genomic surveillance as a proactive strategy to control the spread of carbapenemase-producing K. pneumoniae isolates, particularly when key antimicrobial resistance genes, such as blaNDM-1 and blaKPC-3, are plasmid-mediated. Detailed characterization of these isolates could reveal plasmid similarities that facilitate adaptation and transmission within and between hospitals. Although data on patient movements are limited, it is plausible that carbapenem-resistant isolate was selected to co-produce KPC and NDM through plasmid acquisition.

Bloodstream infections (BSI) result in significant morbidity and mortality rates, and delayed administration of appropriate antimicrobial treatment is a major predictor of poor outcomes. T2 magnetic resonance (T2MR®) (T2 Biosystems®, Lexington, MA, USA) is an innovative technology that can rapidly identify pathogens from a sample of whole blood in a remarkably short time frame of 3-5 h. We are evaluating if the T2Bacteria Panel (T2BP) contributes to the etiological diagnosis of bloodstream infections when combined with standard blood cultures (BC). The study was performed between December 2018 and March 2019, and a total of 28 patients with suspected BSI were included. The most notable finding of our study was that the addition of T2BP to BC in a diagnostic workflow led to a statistically significant higher rate of T2BP-targeted bacteria identification in patients with suspected BSI (46.4% versus 7.1%, P = 0.001) when compared to BC alone. Considering the measures of diagnostic accuracy, T2BP showed 100.00% sensitivity, 88.24% specificity, 100% negative predictive value (NPV), and 84.62% positive predictive value (PPV). Our findings give valuable insights for microbiologists and clinicians into this molecular method and its advantages in routine diagnostics of BSI.

Clostridioides difficile infection (CDI) is one of the most significant causes of diarrhea in hospitalized patients. The aim of this study was to investigate the incidence and epidemiology of CDI after the COVID-19 pandemic in hospitalized patients in a rehabilitation center in Thessaloniki, Greece. Α retrospective observational cohort study was performed in inpatients diagnosed with diarrhea of all ages (January 2023 - December 2023) who were initially screened for CDI. From the total cohort of patients with proven CDI, some patients were randomly selected based on their monthly isolation incidence throughout the study period, to investigate their epidemiological data and clinical characteristics. Laboratory diagnosis of CDI was performed by enzyme immunoassay, followed by specific anaerobic culture and molecular testing for detection of toxigenic C. difficile. The isolated C. difficile strains were further characterized by PCR ribotyping. The annual incidence of CDI during the study period was 27.1% (130/480). The linear trend of CDI incidence decreased from 32.5% to 18.2% (P = 0.024). The all-cause mortality rate was 5.0% (3/60). A positive correlation was observed between the length of hospital stay and the number of recurrences (r = 0.546, P < 0.001), while 28 patients (46.7%) experienced recurrence of the infection. Seven different PCR ribotypes were identified in this study. C. difficile tcdA+, tcdB+, cdtA+, cdtB+ PCR ribotype 181 (RT181) was the predominant (76.6%, 46/60), followed by toxin A-negative PCR RT017 (11.6%, 7/60). The annual incidence of CDI decreased after the COVID-19 pandemic. Our study demonstrates predominance of C. difficile RT181 with tcdA+, tcdB+, cdtA+, cdtB+ toxin gene profile after COVID-19 pandemic in Northern Greece.

Hepatitis C virus (HCV) is a leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma worldwide. HCV has 8 genotypes (GT) and 86 subtypes and distribution of GTs varies based on geographical regions, transmission routes and even in cultural groups. The determination of viral genotype is crucial in choosing antiviral treatment, determining the duration of therapy, and monitoring treatment respose. Since 2014, with the usage of direct-acting antiviral agents (DAAs) in the treatment of HCV infections, a cure rate over 95% could be possible. Epidemiological data are important to combat a chronic HCV infections. Due to its geographical location, Turkey is like a bridge connecting Asia and Europe. Istanbul is the biggest and most crowded city of Turkey and has received immigration from many different countries, especially from Syria, in recent years and immigration still goes on. In addition, the COVID-19 pandemic has had devastating effects in our country. In this study, we determined the HCV genotypes in Health Sciences University Ümraniye Training and Research Hospital, in Istanbul between 2016 and 2022. Of the 322 patients analyzed during this 7-year period, HCV GT1b was the most prevalent GT in 65.2%, followed by GT3 in 15.5%, GT1a in 10.6%. Our data serve as a great mirror for HCV epidemiology in Turkey and contribute to global data.