Acta microbiologica et immunologica Hungarica最新文献

The aim of this study is to detect the carbapenemase type and to determine the in vitro effects of ceftazidime/avibactam-colistin, ceftazidime/avibactam-meropenem and ceftazidime/avibactam-tigecycline combinations against Carbapenem-Resistant Klebsiella pneumoniae (CRKP) isolates. A total of 35 CRKP isolates were included to the study. The minimum inhibitory concentrations of ceftazidime/avibactam, meropenem, colistin and tigecycline were determined by broth dilution method. Synergistic effects of ceftazidime/avibactam-colistin, ceftazidime/avibactam-meropenem and ceftazidime/avibactam-tigecycline were investigated by microdilution checkerboard method. Carbapenemase genes (blaOXA-48, blaNDM, blaKPC, blaIMP, blaVIM) were detected by multiplex PCR. All of the isolates were resistant to meropenem, whereas 77.1% of the isolates were resistant to ceftazidime/avibactam and 14.3% of the isolates were resistant to colistin.The carbapenemase genes of the CRKP isolates were determined as 17 OXA-48+NDM, 9 KPC, 6 OXA-48, 1 NDM, 1 KPC+NDM and 1 KPC+OXA-48. Ceftazidime/avibactam-colistin, ceftazidime/avibactam-meropenem and ceftazidime/avibactam-tigecycline combinations were synergistic against 5.7% (2/35), 17.1% (6/35), and 5.7% (2/35) of the isolates, respectively. Ceftazidime/avibactam-meropenem was the most effective synergistic combination in our study, showing synergism in 17.1% of isolates, however, the synergistic effect varied depending on the CRKP isolate tested.

Vancomycin-intermediate Staphylococcus aureus (VISA) strains represent a serious public health concern. It is crucial to investigate the genetic diversity, biofilm formation, and virulence analysis of VISA isolated from hospitalized patients. During the two-year study period, 42 VISA were obtained from 520 S. aureus isolates collected from various clinical samples, corresponding to a prevalence of 8.1%, as determined by the broth microdilution method. These VISA isolates were further characterized using biofilm formation, antimicrobial susceptibility tests, SCCmec typing, spa typing, multilocus sequence typing (MLST), and PCR analysis for detecting resistance (erm(B), tet(M), mecC, msr(B), mecA, mupA, vanA, aac(6')-Ie/aph(2˝), mupB, msr(A), erm(C), erm(A), vanB, ant(4')-Ia, and aph(3')-IIIa), biofilm (clfA, clfB, fnbA, fnbB, ebp, cna and bap) and virulence (eta, etb, pvl, and tst) genes. Our results indicated that the 42 VISA isolates belonged to three clonal complexes, including CC8 (78.6%), CC22 (11.9%), and CC5 (9.5%). The vast majority of S. aureus isolates belonged to CC8/ST239-SCCmec III/t037 (42.9%). Our result revealed that PVL-positive strains belonged to CC/ST5-SCCmec IV/t002 (9.5%), CC/ST8-SCCmec IV/t008 (19%), and CC/ST22-SCCmec IV/t790 (7.1%) while TST-positive isolates belonged to CC8/ST239-SCCmec III/t030 (9.5%) and CC8/ST239-SCCmec III/t037 (35.7%). The majority of HLMUPR isolates belonged to CC8/ST239-SCCmec III/t037 (14.3%), followed by CC/ST8-SCCmec IV/t008 (7.1%), CC8/ST239-SCCmec III/t030 (4.8%), and CC/ST5-SCCmec IV/t002 (2.4%) lineages carrying mupA. The highest frequency of VISA strain with iMLSB phenotype belonged to the CC8/ST239-SCCmec III/t037 (11.9%) clonal lineage. The study highlights that genetic diversity and characteristics of the VISA strains should be closely and continuously monitored. Besides that, importance of measures to prevent the transmission of VISA to treat such infection were urgently needed.

The emergence of antibiotic-resistant bacteria has increased, making it difficult to treat infections that are associated with increasing morbidity and mortality. The presence of strains resistant to several antibiotics, such as ESBL-producing Escherichia coli (ESBL-EC), in livestock has been reported in several countries, posing a potential risk to consumer health. Therefore, the objective of this study is to evaluate the prevalence and characteristics of ESBL-producing E. coli in poultry in Tamaulipas, Mexico. Poultry cloacal samples were taken for the identification of ESBL-EC, antibiotic susceptibility patterns were determined, the virulence genes (stx1, stx2 and hlyA) and classification of phylogroups were detected by PCR. The results showed an average prevalence of 17.5% (28/160) ESBL-EC strains in poultry. All strains (28/28) were resistant to ampicillin and ceftriaxone. On the contrary, all strains were sensitive to amikacin, netilmicin, and nitrofurantoin. A total of 64.2% (18/28) of strains were MDR. The 32.1% (9/28) of the strains belonged to the B2 and D phylogroups, which are considered pathogenic groups, with 33.3% (3/9) MDR. This indicates that poultry in Ciudad Victoria, Tamaulipas, is a reservoir of pathogenic strains with antibiotic resistance and MDR, which may pose a risk to public health.

Autism is a complex neurodevelopmental disorder characterized by a wide range of cognitive, behavioural and communication impairments. Children with autism have a distinctive and underdeveloped range and volume of gut bacteria (microbiome) which is often not related to their diet. Evidence gathered throughout years of research suggests that the pathway between gut bacteria and the central nervous system, referred to as the gut-brain axis (GBA), has a profound effect on the social behaviours of autistic children. The gut microbiome has been shown to play a vital role in the manifestation of autism spectrum disorder (ASD) symptoms as gut dysbiosis - an imbalance in the gut microbiome - affects brain development through processes regulated by the neuroendocrine, neuroimmune and autonomic nervous systems. Although dysregulation of the gut microbiome and subsequent disruption of GBA are thought to contribute to the pathogenesis of autism, the underlying mechanisms and the extent to which the microbiome contributes to neurodevelopmental disorders remain unclear. In this review, we focus on understanding the complex and multidirectional interplay between gut microbiota and ASD based on evidence mounted over the years. Furthermore, we examine how genomics, metabolomics and microbiome components can be integrated to unravel this multifactorial disorder. The ability to understand the underlying mechanisms involved in ASD will pave the way for future advancements in therapy and treatment.

This study aimed to examine the relationship between gut microbiome diversity, immune modulation, and allergen immunotherapy (AIT) effectiveness in patients with allergic rhinitis (AR). A prospective cohort study was conducted on 450 participants: 300 adult patients with allergic rhinitis, who were eligible for AIT, and 150 healthy controls. The Total Nasal Symptom Score (TNSS) and the Rhinitis Quality of Life Questionnaire (RQLQ) were used to assess symptom severity and the impact of AR on daily life. Blood and stool samples were collected at baseline and after six months of AIT for microbiome analysis. The stool samples were analyzed with the 16S rRNA gene V4 region, followed by sequencing on the Illumina MiSeq platform. The microbial composition and diversity were assessed using the QIIME2 pipeline, and taxonomic assignments were made using the SILVA reference database. Short-chain fatty acids (SCFAs) were quantified using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). Flow cytometry was used to quantify T-regulatory cells (Tregs). Cytokine levels (IL-10, IL-4, IFN-γ) were measured using enzyme-linked immunosorbent assays (ELISA). Allergic rhinitis patients and healthy controls were matched for age and weight; however, AR patients had a significantly higher BMI (P = 0.0006). Baseline TNSS and RQLQ scores were significantly worse in AR patients compared to controls (P < 0.001), but both improved significantly after six months of AIT (P < 0.001). AR patients demonstrated reduced gut microbial diversity (P = 0.028), distinct microbial profiles, and lower levels of SCFAs, indicative of dysbiosis. Immune markers in AR patients revealed lower levels of IL-10 and T-regulatory cells (P < 0.05, P < 0.001) and higher levels of IL-4 and Th2 cells (P < 0.001). Proteobacteria were associated with a decrease in TNSS and an improvement in RQLQ scores (P < 0.05). Allergen immunotherapy improves symptoms and quality of life in AR patients. This may potentially influence immune and microbial imbalances. Proteobacteria may have a protective role in allergic rhinitis, suggesting their potential as a biomarker or therapeutic target in the management of AR.

Bordetella pertussis, the pathogen responsible for a highly contagious respiratory disease, utilizes a broad spectrum of virulence factors that results in subacute or chronic cough.We conducted an analysis of pertussis incidence and reported cases in the European region from 2000 to 2024. We analyzed the potential factors contributing to the rise in pertussis incidence despite high vaccination rates.In 2024, the Slovak Republic and surrounding Central European countries (the Czech Republic, Austria, Hungary, Poland, and Ukraine) have seen a significant increase in pertussis incidence. The results of this study suggest that the resurgence of pertussis was likely due to multiple interacting factors including waning immunity in adults, the genomic changes of B. pertussis, the "immune debt" phenomenon following the lifting of COVID-19 restrictions, the lower vaccination rate against pertussis due to refusal to be vaccinated, a shorter duration of protection offered by acellular vaccines, the transmission of B. pertussis from asymptomatic individuals or patients with mild infection to pertussis-susceptible individuals, as well as improved diagnostics and surveillance.Unimmunised or partially immunised infants are at the highest risk of severe pertussis. The most common sources of infection are family members with asymptomatic or mildly symptomatic disease. All patients with chronic cough should be tested for B. pertussis as part of a comprehensive diagnostic evaluation. To protect newborns, booster vaccination of parents, close family contacts and certain healthcare professionals carrying for the youngest children is recommended. This strategy helps to create a protective environment around infants in the period of pertussis resurgence.

Herein we present a case of a 12-year-old child with acute symptoms (abdominal pain, fever). Preliminary imaging suggested pyogenic liver abscess. Despite the broad-spectrum antibiotic therapy, which was started after hospital admission, no improvement was perceived. Rising eosinophilia and multiplex focal lesions detected by ultrasound and MRI forced serological investigation by which Echinococcus granulosus s.l. seropositivity was detected. Antihelminthic therapy was initiated and upon multidisciplinary consultation surgical intervention was performed with the removal of a cystic lesion which ruptured to the peritoneal cavity. Histopathological and parasitological analysis finally verified alveolar echinococcosis (AE) caused by Echinococcus multilocularis. As the evacuation of one lesion cannot be regarded as curative intervention in this form of echinococcosis, albendazole was administered continuously until patient's medical condition improved and no progression was detected during imaging follow-up. In Hungary both cystic and alveolar echinococcosis are present therefore differential diagnosis of these two forms can be a clinical challenge. Slow rate of progression, long lasting asymptomatic period and relatively low incidence of AE disease can explain that cases during childhood are rarely identified. After reviewing all relevant literature in this topic, we present here the first pediatric AE case in Hungary.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a growing threat in Greek hospitals, with increasing reports of multidrug- and pandrug-resistant strains; however, molecular data from regional centers remain limited. This study aimed to investigate the molecular epidemiology, resistance mechanisms, and transmission dynamics of CRKP isolates collected at the General Hospital of Volos, Central Greece, between 2022 and 2024. Thirty-seven non-duplicate CRKP isolates were analyzed. Identification and antibiotic susceptibility testing were performed using VITEK® 2, disk diffusion, Etest®, and broth microdilution. Carbapenemase production was assessed using the NG-Test® Carba-5. Eight isolates underwent multilocus sequence typing (MLST). All isolates were resistant to carbapenems, cephalosporins, and fluoroquinolones; furthermore, 40% were colistin-resistant. The dominant carbapenemase genes were blaNDM-1 (45.9%), blaKPC-2 (18.9%), and blaVIM-1 (27.0%), with co-expression of multiple carbapenemases in 30% of the isolates. MLST revealed the high-risk clones ST11, ST15, and ST323, and three intra-intensive care unit (ICU) transmission clusters. The emergence of dual-carbapenemase and colistin-resistant clones underscores the need for local genomic surveillance, improved infection control, and access to newer antimicrobials in non-tertiary settings.

Products of avian origin are one of the major Salmonella reservoirs, responsible for serious public health concerns. Transmission and pathogenicity are mainly caused by molecular mechanisms, including chromosomal and plasmid-encoded virulence factors. This study aimed to perform phenotypic identification, antibiotic resistance profiling against 15 antibiotics, and characterization of virulence factors of 80 Salmonella strains (30 from human and 50 from poultry), collected in Annaba and Constantine regions in Algeria.Antibiogram analysis and simplex PCR revealed complete resistance to four antibiotics: Ampicillin, Penicillin, Cephalotin and Cephoxetin. In addition, four virulence genes (spvA, spiC, spvC and pefA) were detected. These genes were identified in isolates from both avian and human origins, with variations in their distrubition frequencies. This study highlights the significant role of avian-derived Salmonella as a reservoir of antibiotic resistance and virulence genes, posing a serious threat to public health.Antibiotic resistance profiling revealed that avian isolates exhibited complete resistance (100%) to ampicillin, penicillin and cephalothin, followed by a high resistance rate of 98% to cefalexin and ceftriaxone. Moderate resistance levels, ranging from 76% to 46%, were observed against streptomycin, tetracycline, trimethoprim-sulfamethoxazole, ciprofloxacin, kanamycin and nalidixic acid. In contrast, low resistance rates were reported for gentamicin, amikacin, and chloramphenicol, at 20%, 18%, and 16%, respectively.On the other hand, human isolates showed complete resistance (100%) to ampicillin, penicillin, cephalothin and cefalexin. Moderate resistance (76%-46%) was observed against ceftriaxone, kanamycin, cefotaxime, gentamicin, trimethoprim-sulfamethoxazole, nalidixic acid, streptomycin, and chloramphenicol. Low resistance levels were detected for tetracycline, ciprofloxacin, and amikacin, at 26%, 20%, and 6.6%, respectively.These findings along with the widespread presence of virulence genes (spvA, spiC, spvC, and pefA) in both human and poultry isolates, underscore the potential for cross-species transmission and the urgent need for enhanced surveillance. The regional findings from Annaba and Constantine emphasize the importance of stricter antibiotic use policies in poultry farming.

The objective of our work is to identify antimicrobial-resistance genes and to analyze clonality of carbapenem-resistant Escherichia coli. A total of 75 carbapenem-resistant E. coli (CREco) strains were isolated in a Chinese hospital from January 2021 to May 2023. The antibiotic susceptibility testing was conducted by BD PhoenixTM M50 System and Kirby-Bauer disk diffusion method. Whole-genome sequencing was performed on Illumina NovaSeq 6000 platform. Antimicrobial resistance genes were identified based on NCBI with ABRicate 0.8. Multilocus sequence typing (MLST) analysis for CREco was performed. Among the 75 CREco strains in this study, the most of them were isolated from urine samples (n = 20, 26.67%) at the intensive care unit (n = 14, 18.67%). Among the detected carbapenem resistance genes, blaNDM-5 was the most prevalent (n = 57, 76.00%), followed by blaNDM-4 (n = 3, 4.00%), blaNDM-9 (n = 3, 4.00%), and blaNDM-1 (n = 2, 2.67%). In addition, the colistin resistance gene mcr-1.1 (n = 11, 14.67%) and the tigecycline resistance gene tetX4 (n = 2, 2.67%) were also detected. The results of MLST revealed 25 sequence types (STs), and ST410 (n = 17) was the dominant clone. Other major STs included ST167 (n = 12), ST156 (n = 10), ST361 (n = 5), and ST101 (n = 4). Overall, CREco strains exhibited a high-level resistance rate to commonly used antimicrobial agents, and the most of them carried various NDM-coding genes, with blaNDM-5 being the predominant type. In this study, we demonstrated the diversity of carbapenem-resistant E. coli; however, the major clone was ST410. These results also show the dissemination of different clones of carbapenem-resistant E. coli.