Acta Microbiologica Et Immunologica Hungarica[JOURNAL]
Sun
200 papers
Anaerobic bacteria from bloodstream infections: Identification and antibacterial susceptibility testing in a single center in Türkiye.
Orak F, Karakaya E, Saticioğlu İB … +4 more , Akar M, Güran C, Abay S, Aydin F
Acta Microbiol Immunol Hung · 2025 Mar · PMID 39928062 · Publisher ↗
This study aimed the identification of anaerobic bacteria isolated from blood cultures and the determination of antibacterial susceptibility of the isolates. The study material comprised of 5,282 blood samples taken betw...
This study aimed the identification of anaerobic bacteria isolated from blood cultures and the determination of antibacterial susceptibility of the isolates. The study material comprised of 5,282 blood samples taken between 2018 and 2020. The samples were incubated in a BacT/ALERT system. The species identification of the isolates was performed by three methods namely, BBL Crystal Anaerobe system, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16S rRNA gene sequence analysis. Antibacterial susceptibility testing was performed using the disk diffusion method with benzylpenicillin, clindamycin, piperacillin-tazobactam, meropenem, and metronidazole disks. In the BacT/ALERT system, 45 anaerobic bacterial isolates were recovered from 39 (0.74%) of the samples that showed growth signs in blood culture bottles. The BBL Crystal Anaerobe system and 16S rRNA gene sequence analyses enabled the genus and species identification of all 45 isolates (100%), whereas with MALDI-TOF MS, only 37 (82.2%) of the isolates were able to be identified. Antibacterial resistance rates of the isolates to piperacillin/tazobactam, clindamycin, benzylpenicillin, meropenem, and metronidazole were detected as 100%, 73.8%, 40%, 9.8%, and 5.5%, respectively. MALDI-TOF MS showed a higher level of compatibility with 16S rRNA gene sequence analyses, compared to the BBL Crystal Anaerobe system. The high rates of susceptibility to meropenem and metronidazole suggested that these antibiotics are options for the empirical treatment of anaerobic bacterial infections.
Antimicrobial resistance pattern of the Bacteroides fragilis group strains isolated at a teaching hospital in China.
Wu ZC, Feng HX, Wu L … +2 more , Zhang M, Gu Z
Acta Microbiol Immunol Hung · 2025 Mar · PMID 39907717 · Publisher ↗
The study was conducted in the microbiology laboratory of the First Affiliated Hospital of Hainan Medical University, Haikou, China, from January 2019 to December 2023. A total of 316 consecutive non-duplicate isolates w...
The study was conducted in the microbiology laboratory of the First Affiliated Hospital of Hainan Medical University, Haikou, China, from January 2019 to December 2023. A total of 316 consecutive non-duplicate isolates were collected and identified, that belonged to the Bacteroides fragilis group. Identification of the isolated strains was performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The minimum inhibitory concentration (MIC) of seven antibiotics was determined by agar dilution method. The presence of cfiA, ermF, and nim genes was determined by polymerase chain reaction (PCR). Correlations between the presence of resistance genes and the MIC values of antibiotics were determined using the Pearson correlation coefficient. In the identification process, 214 isolates (67.7%) were identified as B. fragilis, 52 (16.4%) as Bacteroides thetaiotaomicron, 17 (5.4%) as Bacteroides ovatus, 12 (3.8%) as Bacteroides uniformis, 10 (3.2%) as Phocaeicola vulgatus (=Bacteroides vulgatus), 7 (2.2%) as Bacteroides stercoris, and 4 (1.3%) as Parabacteroides distasonis. The presence of cfiA gene moderately correlated with the MIC of imipenem and meropenem (r = 0.34 and r = 0.42, respectively), while resistance to clindamycin and the presence of ermF gene exhibited a very strong correlation (r = 0.72). In the current study, the most active antimicrobial agents against B. fragilis group bacteria were found to be meropenem, imipenem, metronidazole, and piperacillin/tazobactam; however, resistance to clindamycin renders its empirical use inappropriate.
Identification of NDM-1 producing and colistin resistant Klebsiella pneumoniae ST11: A highly drug-resistant strain detected in intensive care unit of a Greek tertiary care hospital.
Chatzidimitriou M, Tsolakidou P, Kyriazidi MA … +6 more , Chatzopoulou F, Varlamis S, Mavridou M, Kalinderi K, Kyriazidis KA, Mitka S
Acta Microbiol Immunol Hung · 2025 Mar · PMID 39847027 · Publisher ↗
The spread of NDM-1-harboring Klebsiella pneumoniae is a worldwide concern. In this study the whole-genome sequence (WGS) of a carbapenem- and colistin-resistant K. pneumoniae 838Gr strain is presented. This strain was i...
The spread of NDM-1-harboring Klebsiella pneumoniae is a worldwide concern. In this study the whole-genome sequence (WGS) of a carbapenem- and colistin-resistant K. pneumoniae 838Gr strain is presented. This strain was isolated from a urine sample of a patient in the Intensive Care Unit (ICU) at Volos Hospital, Greece. The initial assembly produced 224 contigs with a combined genome size of 5,561,803 bp and a GC content of 57.21%. The K. pneumoniae strain carried IncR, IncFIA, IncC, and repB (R1701) replicons. Multilocus sequence typing (MLST) analysis revealed that the isolate belonged to the sequence type 11 (ST11) and serogroup KL24 and O2a. The WGS analysis identified several beta-lactamase genes (blaTEM-1B, blaCTX-M-15, blaNDM-1, blaOXA-1, blaVEB-1, blaOXA-10, and blaSHV-11) alongside resistance genes for other antibiotic classes, including floR2, cmlA1, cmlA5, catB3, arr-3, aph(6)-Id, aadA2. Colistin resistance was attributed to specific point mutations in pmrB (R256G, T140P). This is the first report of a carbapenem- and colistin-resistant K. pneumoniae ST11 strain in Greece. The findings of this study highlight the urgent need for increased surveillance and stringent infection control.
Application of metagenomic next-generation sequencing in pathogen detection for patients with lower respiratory tract infections caused by multidrug-resistant organisms and analysis of related factors.
Zhao Y, Mao R, Zhong Y … +4 more , Lu J, Gong B, Yi W, Zeng Z
Acta Microbiol Immunol Hung · 2024 Dec · PMID 39688617 · Publisher ↗
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...
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).
Aerococcus urinae urinary tract infections: A case series.
Maraki S, Mavromanolaki VE, Stafylaki D
Acta Microbiol Immunol Hung · 2024 Dec · PMID 39688613 · Publisher ↗
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 urin...
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.
Investigation of the synergistic effect of ceftazidime-avibactam and aztreonam combination on carbapenem-resistant Klebsiella pneumoniae isolates with 3 different methods.
Uzunöner Y, Kansak N, Aksaray S
Acta Microbiol Immunol Hung · 2024 Dec · PMID 39688612 · Publisher ↗
Treatment options are limited for infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates due to the production of metallo-β-lactamase (MBL). The ceftazidime-avibactam (CZA)/ aztreonam (ATM) combi...
Treatment options are limited for infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates due to the production of metallo-β-lactamase (MBL). The ceftazidime-avibactam (CZA)/ aztreonam (ATM) combination represents a new therapeutic approach in MBL-positive isolates. Our study aims to determine distribution of carbapenemase genes in CRKP isolates and to investigate the in vitro synergistic effect of the CZA/ATM combination.Our study included 48 CRKP strains isolated from various clinical samples. Identification was performed using MALDI-TOF MS (bioMérieux, France), and susceptibility was tested with Vitek-2 (bioMérieux). The susceptibility to CZA and ATM was determined using CZA 30/20 µg and ATM 30 µg (Oxoid™,UK) disks. Carbapenemase genes VIM, NDM, IMP, KPC, OXA-23, OXA-58, OXA-48, and OXA-51 were investigated in only 44 isolates using the Bio-Speedy Carbapenem resistance qPCR (Bioexen, Turkiye) kit. Synergy testing was evaluated with double disk diffusion, gradient strip (bioMérieux)/disk diffusion, and broth disk elution methods.Out of 48 carbapenem-resistant isolates, 40 (83.3%) isolates showed resistance to CZA and 46 (95.8%) to aztreonam. Synergy was detected with all three methods in all isolates identified as resistant to CZA, CZA-sensitive isolates were not included in this evaluation. The most frequently detected carbapenemase genes were NDM+OXA-48, found in 28 (63.6%) of the isolates.Although the NDM+OXA-48 coexistence predominates in our center, in vitro synergy between CZA and ATM was detected in all of CZA-resistant isolates. Performing the CZA+ATM synergy test and reporting the result is crucial for choosing appropriate treatment in CRKP infection.
Characterization of a carbapenemase-producing Klebsiella pneumoniae isolate of a patient in an intensive care unit in Greece: A study of resistome, virulome, and mobilome.
Tsolakidou P, Papadimitriou A, Kyriazidis KA … +3 more , Ilias P, Mitka S, Chatzidimitriou M
Acta Microbiol Immunol Hung · 2024 Dec · PMID 39671000 · Publisher ↗
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, OX...
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.
High prevalence of CTX-M-15 producing Shigella spp. isolated from patients with gastroenteritis in Northeast Iran.
Khosravi M, Khosravi F, Pouresmaeil O … +4 more , Aryan E, Meshkat Z, Safdari H, Farsiani H
Acta Microbiol Immunol Hung · 2024 Dec · PMID 39625531 · Publisher ↗
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 o...
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.
NDM-1 and KPC-3 co-producing Klebsiella pneumoniae ST512 in bronchial secretion from a patient in an intensive care unit of a Greek Tertiary Care Hospital.
Chatzidimitriou M, Tsolakidou P, Voulgaridis A … +6 more , Kyriazidi MA, Chatzopoulou F, Mavridou M, Varlamis S, Mitka S, Vagdatli E
Acta Microbiol Immunol Hung · 2024 Dec · PMID 39601796 · Publisher ↗
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 suc...
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.
T2Bacteria panel used simultaneously with blood cultures helps to determine the etiology of bloodstream infections.
Peras M, Kuliš T, Mareković I
Acta Microbiol Immunol Hung · 2024 Dec · PMID 39560688 · Publisher ↗
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...
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.
Epidemiology of Clostridioides difficile PCR ribotype 181 after the COVID-19 pandemic in Northern Greece.
Charisi E, Tsioka K, Karampatakis T … +1 more , Kachrimanidou M
Acta Microbiol Immunol Hung · 2024 Dec · PMID 39466344 · Publisher ↗
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 pande...
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.
HCV genotype distribution in Istanbul: A detailed 7 year epidemiological overview and impact of Covid-19 pandemic.
Erdin BN, Akkaya Y, İrvem A
Acta Microbiol Immunol Hung · 2024 Dec · PMID 39432366 · Publisher ↗
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 region...
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.
Detection of KPC-3 producing Escherichia coli ST410 in Volos, Greece.
Chatzidimitriou M, Tsolakidou P, Kyriazidi MA … +1 more , Mitka S
Acta Microbiol Immunol Hung · 2024 Dec · PMID 39287989 · Publisher ↗
Escherichia coli A382 was isolated in July 2024 from a positive blood culture obtained from the central venous catheter of a male patient undergoing chemotherapy at the Hospital of Volos, Thessaly, Greece. Whole-genome s...
Escherichia coli A382 was isolated in July 2024 from a positive blood culture obtained from the central venous catheter of a male patient undergoing chemotherapy at the Hospital of Volos, Thessaly, Greece. Whole-genome sequencing analysis revealed that the isolate A382 is E. coli belonging to the ST410 high-risk clone, which co-harbors the blaKPC-3 and blaSHV-182 genes on an IncX3 plasmid. It also harbors blaTEM-1 and has five replicons, as follows: IncX3, IncQ1, CoIRNAI, IncF1A, and IncFIB. Complete genome analysis revealed that E. coli A382 isolate carries a range of virulence factors (iutA, iucC, fimH, fdeC, yehA, yehD, yehC, yehB, cgs, ahha, ccI, hlyE, papC, irp2, fyuA, lpfA, and nlpl) and many other non-beta-lactam resistance determinants, including dfrA14 and sul2, but it is susceptible to aminoglycosides, nitrofurantoin, tigecycline, colistin and ceftazidime-avibactam. In conclusion in this study, we describe the phenotypic and genome characteristics of an extensively drug-resistant E. coli ST410.
Antibiotic resistant Escherichia coli strains in healthy pets from Tamaulipas, Mexico.
Mandujano-Hernández JA, Vázquez-Villanueva J, De Luna-Santillana EJ … +3 more , Rivera G, Bocanegra-García V, Martínez-Vázquez AV
Acta Microbiol Immunol Hung · 2024 Sep · PMID 39264714 · Publisher ↗
Antibiotic resistance constitutes a significant public health challenge, with diverse reservoirs of resistant bacteria playing pivotal roles in their dissemination. Among these reservoirs, pets are carrying antibiotic-re...
Antibiotic resistance constitutes a significant public health challenge, with diverse reservoirs of resistant bacteria playing pivotal roles in their dissemination. Among these reservoirs, pets are carrying antibiotic-resistant strains. The objective of this study was to assess the resistance profiles of Escherichia coli, and the prevalence of extended-spectrum β-lactamase (ESBL) producing E. coli strains in dogs and cats from Tamaulipas, Mexico. A total of 300 stool samples (150 dogs and 150 cats) from healthy pets were subjected to analysis. Antibiotic susceptibility testing and the identification of ESBLs were carried out by disc diffusion method. The presence of resistance genes, class 1, 2, and 3 integrons (intI1, intI2, and intI3) and phylogroups was determined by PCR analysis. The findings reveal that 42.6% (128/300) of the strains exhibited resistance to at least one of the eight antibiotics assessed, and 18.6% (56/300) demonstrated multidrug resistance (MDR), that distributed across 69 distinct resistance patterns. Altogether 2.6% of E. coli strains (8/300) were confirmed as TEM and CTX-M type ESBL producers. These outcomes underscore the roles of dogs and cats in Tamaulipas as reservoirs for the dissemination of MDR and/or ESBL strains. The results underscore the necessity for conducting prevalence studies on ESBL-producing E. coli, forming a foundation for comprehending the present scenario and formulating strategies for the control and mitigation of this issue.
Prevalence and characteristics of ESBL-producing Salmonella in Weifang, China.
Wang X, Wang B, Lu X … +3 more , Ma J, Wang Z, Wang Y
Acta Microbiol Immunol Hung · 2024 Sep · PMID 39226121 · Publisher ↗
This study examined the prevalence and antibiotic resistance pattern of blaCTX-M extended-spectrum β-lactamase positive Salmonella species isolated from a hospital in Weifang. Salmonella strains were isolated from hospit...
This study examined the prevalence and antibiotic resistance pattern of blaCTX-M extended-spectrum β-lactamase positive Salmonella species isolated from a hospital in Weifang. Salmonella strains were isolated from hospitalized patients from January 2018 to April 2023. Whole-genome sequencing was performed by Illumina platform. CTX-M-producing Salmonella were identified by Comprehensive Antibiotic Research Database (CARD). Strain susceptibility to six antimicrobial agents was assessed by BD Phoenix™ M50 System. MLST analysis confirmed sequence types and additionally, serotypes were determined by SeqSero2. Genetic environments of blaCTX-M genes were analyzed by Isfinder and BLASTn. Single nucleotide polymorphisms were used to construct a phylogenetic tree to analyze homology. A total of 34 CTX-M-producing Salmonella were detected. The most prevalent serotype was Salmonella enterica subsp. enterica 1,4,[5],12:i:- (14/34, 41.18%), belonging to ST34, followed by Salmonella Enteritidis (10/34, 29.41%), belonging to ST11. The highest resistance rate was detected to ampicillin (97.06%), followed by ceftriaxone (94.12%) and ceftazidime (58.83%). In CTX-M-producing Salmonella five types of blaCTX-M genes were identified, the most prevalent was blaCTX-M-55 (47.06%, 16/34), followed by blaCTX-M-14, blaCTX-M-65, blaCTX-M-125, and blaCTX-M-27 at 26.47% (9/34), 11.77% (4/34), 8.82% (3/34), and 5.88% (2/34), respectively. Apart from blaCTX-M, 40 antibiotic resistance genes were also detected, conveying resistance to multiple drugs and the most frequent genes were namely, mcr-1.1, aph(6)-Id, aph(3″)-Ib, oqxAB, qnrB6, qnrS1. According to genetic environment analysis, the insertion sequence ISEcp1 was prevalent upstream of the blaCTX-M gene. Our study demonstrates that multiple resistance genes are carried by clinical isolates of Salmonella spp. however, the dominant ESBL genotype is CTX-M-55, that is associated with ISEcp1.
Outbreak caused by multidrug-resistant OXA-48 and NDM-1 producing Klebsiella pneumoniae in the intensive care unit of a cancer hospital.
Süzük Yıldız S, Tavukcu E, Şahin S … +7 more , İskender G, Ünaldı Ö, Demirhan B, Avşar Z, Orman EÖ, Mumcuoğlu İ, Dal T
Acta Microbiol Immunol Hung · 2024 Sep · PMID 39207858 · Publisher ↗
We report a nosocomial outbreak caused by a multidrug-resistant carbapenemase-producing Klebsiella pneumoniae (MDRCPKp), that was detected in six patients admitted to the medical intensive care unit between 20th of Decem...
We report a nosocomial outbreak caused by a multidrug-resistant carbapenemase-producing Klebsiella pneumoniae (MDRCPKp), that was detected in six patients admitted to the medical intensive care unit between 20th of December 2023 and 15th of January 2024 in Ankara, Turkey. The investigation of this outbreak was started on 29th of December 2023. During the outbreak 11 samples were collected from the six patients with MDRCPKp. Pulsed-field gel electrophoresis (PFGE) was performed to determine the genetic relatedness and clonality of MDRCPKp strains. MDRCPKp was isolated in the tracheal aspiration culture, blood, urine, and screening samples. Five patients with MDRCPKp colonization developed healthcare-associated infection. In one patient MDRCPKp was isolated from tracheal aspirate and the screening cultures were considered as colonization not infection. PFGE analysis revealed that all isolates belonged to the same K. pneumoniae clone. MDRCPKp strain of this outbreak exhibited multidrug resistance and co-produced OXA-48 and NDM-1. This outbreak ended after application of strict infection control measures. An outbreak of MDRCPKp can occur in hospitals, especially in the intensive care units; thus, it should be detected early by infection control teams. A strong collaboration between infection control team and microbiology laboratory is essential to cope with MDR bacterial outbreaks in hospitals.
ESKAPE pathogens in pediatric cardiac surgery patients: 5-year microbiological monitoring in a tertiary hospital in Kazakhstan.
Baigenzhin A, Bissenova N, Yergaliyeva A … +3 more , Marassulov S, Tuleubayeva E, Aitysheva U
Acta Microbiol Immunol Hung · 2024 Sep · PMID 39190489 · Publisher ↗
Hospital acquired infections greatly affect recovery and survival in pediatric surgical patients. We evaluated prevalence and antimicrobial resistance of ESKAPE pathogens in neonates and infants subjected to cardiac surg...
Hospital acquired infections greatly affect recovery and survival in pediatric surgical patients. We evaluated prevalence and antimicrobial resistance of ESKAPE pathogens in neonates and infants subjected to cardiac surgery in a tertiary hospital in Central Kazakhstan between 2019 and 2023 (2,278 patients) using routine methods of microbiological detection. ESKAPE pathogens were found in 1,899 out of 2,957 samples (Staphylococcus aureus - 35.3%, Klebsiella pneumoniae - 27.8%, Acinetobacter baumannii - 14.5%, Pseudomonas aeruginosa - 12.4%, Enterobacter sp. - 8.8%, Enterococcus faecium - 1.2%). The total prevalence of ESKAPE increased significantly from 45.1 to 76.9% (P = 0.005) during the study period. The resistance significantly increased in methicillin-resistant S. aureus (MRSA, from 13.7 to 41.9%, P = 0.041) but decreased in carbapenem-resistant P. aeruginosa (from 64.3 to 37.7%, P = 0.037) and carbapenem-resistant A. baumannii (from 48.5 to 19.1%, P = 0.039). Gradual but non-significant changes were shown in third-generation cephalosporin resistant K. pneumoniae (from 63.6 to 45.2%) and carbapenem-resistant K. pneumoniae (from 0 to 8.3%). The relative prevalence of ESKAPE pathogens steadily increased in our pediatric cardiac surgery patients in 2019-2023. The most frequent were S. aureus, K. pneumoniae, and A. baumannii, with dramatically increasing tendencies for MRSA. Our results highlight the necessity for a well-designed infection control strategy and constant microbiological monitoring in pediatric cardiac surgery departments.
Case report of an abdominal wet gangrene caused by Acidaminococcus.
Fakhfakh A, Ferjani S, Kanzari L … +10 more , Ferjani A, Hamzaoui Z, Rehaiem A, Ben Dhaou A, Aloui M, Karoui Y, Syala N, Bouaani H, Ben Moussa M, Ben Boubaker IB
Acta Microbiol Immunol Hung · 2024 Sep · PMID 39186383 · Publisher ↗
The Acidaminococcus genus is a part of the normal flora in gastrointestinal tract. It is a strictly anaerob Gram-negative coccus that is rarely pathogenic. We report the case of a 58-year-old man, who presented to surger...
The Acidaminococcus genus is a part of the normal flora in gastrointestinal tract. It is a strictly anaerob Gram-negative coccus that is rarely pathogenic. We report the case of a 58-year-old man, who presented to surgery department A of the Charles Nicolle hospital, complaining of a wide inflammatory lesion in the anterior abdominal wall evolving for two weeks. Patient's anamnestic data included smoking, hypertension, and diabetes mellitus with poor compliance. The patient underwent flattening with excision of necrotic tissues and surgical drainage using a DELBET blade. Empirical antibiotic therapy with imipenem 1gx3/d, teicoplanin 400 mg 1 inj x2/d and gentamicin 400 mg 1 inj/d was administered pending bacteriological results. The bacteriological examination of a sample of necrotic tissue, after 72 h of incubation at 37 °C in anaerobic atmosphere, was able to detect a Gram-negative coccus, that the VITEK2 ANC system identified as Actinomyces canis with an accuracy of 80%. Whole genome sequencing was subsequently performed, that identified Acidaminococcus sp. AM33-14BH and demonstrated the following resistance genes: cfxa, tet(X) and tet(Q). An antibiogram for anaerobes was performed showing that the strain was resistant to amoxicillin but sensitive to amoxicillin-clavulanic acid, piperacillin-tazobactam, ertapenem, imipenem, meropenem and rifampin. Patient's condition improved after treatment with imipenem for 2 weeks, followed by oral amoxicillin-clavulanic acid for 16 days.This work highlights the role of molecular biology in the diagnosis of infections caused by anaerobes. Although the Vitek 2 ANC card provides rapid and acceptable identification of the most common anaerobic bacteria, improvements are needed for the identification of bacteria in the genera Acidaminococcus and Actinomyces.
Genomic characterization of an uncommon Delftia acidovorans isolate obtained from a Bulgarian immunocompetent outpatient diagnosed with bronchitis.
Peykov S, Gergova R, Atanasova S … +2 more , Dimov SG, Strateva T
Acta Microbiol Immunol Hung · 2024 Sep · PMID 39186382 · Publisher ↗
Delftia acidovorans is an aerobic, non-fermenting Gram-negative bacterium (NFGNB), found in soil, water and hospital environments. It is rarely clinically significant, most commonly affecting hospitalized or immunocompro...
Delftia acidovorans is an aerobic, non-fermenting Gram-negative bacterium (NFGNB), found in soil, water and hospital environments. It is rarely clinically significant, most commonly affecting hospitalized or immunocompromised patients. The present study aimed to explore the genomic characteristics of a Bulgarian clinical D. acidovorans isolate (designated Dac759) in comparison to all strains of this species with available genomes in the NCBI Genome database (n = 34). Dac759 was obtained in 2021 from the sputum of a 65-year-old female immunocompetent outpatient with bronchitis. Species identification using MALDI-TOF mass spectrometry, antimicrobial susceptibility testing, whole-genome sequencing (WGS), and phylogenomic analysis were performed. The isolate demonstrated high-level resistance to colistin (16 mg L-1); resistance to gentamicin; reduced susceptibility to piperacillin, piperacillin-tazobactam, ceftazidime, cefepime, ciprofloxacin, and levofloxacin; and susceptibility to imipenem, meropenem, amikacin, and tobramycin. The observed genome size (6.43 Mb) and GC content (66.76%) were comparable with the accessible data from sequenced D. acidovorans genomes. A limited number of resistance determinants were identified in the assembled genome as follows: blaOXA-459, emrE, oqxB, and mexCD-oprJ. The phylogenomic analysis indicated a high heterogenicity of the included D. acidovorans genomes. In conclusion, to the best of our knowledge, this is the first documented case of a clinically relevant D. acidovorans isolate in Bulgaria. Unlike the majority of reports in the literature, Dac759 affected a patient with no malignancies or other preexisting comorbidities. With this in mind, its genome sequence is a valuable resource for the fundamental study of uncommon bacterial pathogens of public health importance.
Characterization of the vaginal microbiota in infertile women with repeated implantation failure.
Liu L, Feng T, Liu Q … +3 more , Liao M, Liu B, Li M
Acta Microbiol Immunol Hung · 2024 Sep · PMID 39178040 · Publisher ↗
Although the relationship between vaginal microorganisms and fertility has been well established, only few studies have investigated vaginal microorganisms in women undergoing in vitro fertilization (IVF). Our aim was to...
Although the relationship between vaginal microorganisms and fertility has been well established, only few studies have investigated vaginal microorganisms in women undergoing in vitro fertilization (IVF). Our aim was to study the differences in vaginal microbiota between infertile women with repeated implantation failure (RIF) and those who achieved clinical pregnancy in their first frozen embryo transfer cycle. We compared the vaginal microbiota of patients with a history of RIF (n = 37) with that of the control group (n = 43). Following DNA extraction, metagenomic sequencing was employed for the analysis of alpha and beta diversities, distinctions in bacterial species, and the functional annotation of microbial genes. Furthermore, disparities between the two groups were revealed. Alpha diversity analysis revealed that the Shannon index was higher in the RIF group (P < 0.05). There were differences in the beta diversity between groups (P = 0.16). At the bacterial family level, the relative abundance of Actinomycetaceae (P = 0.013) and Ruminococcaceae (P = 0.013) were significantly higher in the RIF group. At the genus level, the abundances of Actinomyces (P = 0.028) and Subdoligranulum (P = 0.013) were significantly higher in the RIF group. At the species level, the abundances of Prevotella timonensis (P = 0.028), Lactobacillus jensenii (P = 0.049), and Subdoligranulum (P = 0.013) were significantly higher in the RIF group. Significant differences in family, genus, species, alpha and beta diversity were observed in the vaginal microbiota between groups. Notably, among these findings, the Subdoligranulum genus emerged as the most prominent correlating factor.
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