Diagnostic microbiology and infectious disease最新文献

Eravacycline is a third-generation tetracycline, a fluorocycline agent with two modifications that distinguish it from tigecycline. Eravacycline demonstrated effectiveness against various gram-positive and gram-negative facultatively anaerobic bacteria, including multidrug resistant Enterobacterales, Acinetobacter baumannii, staphylococci, enterococci, and pneumococci. However, whereas numerous studies focused on the impact of eravacycline on facultative anaerobic microbes, there is limited data regarding its efficacy against anaerobes. The aim of the present review was to compare eravacycline activity to that of other antibiotics used against anaerobic/microaerophilic bacteria and to assess potential benefits of the newer agent in anaerobic or mixed aerobic-anaerobic infections. We encompassed information from the literature published in English and included our own pilot study. Compared to most comparator antibiotics, eravacycline was more effective against anaerobes, including Bacteroides/Parabacteroides, Prevotella, Fusobacterium, Clostridioides difficile and other clostridial species, as well as gram-positive anaerobic cocci, and Cutibacterium acnes. Most frequently, eravacycline MICs were ≥4 to ≥8-fold lower than those of most comparator antibiotics. In addition, eravacycline did not trigger an infection with C. difficile and is considered a tolerable medication. So far, only the injectable eravacycline administration for complicated intraabdominal infections has been approved. However, more studies in more countries are needed to assess its usefulness for combination treatment and still not labeled indications.

Hafnia alvei is a rare cause of human infection and possesses a chromosomal AmpC β-lactamase. Among 30 adults with H. alvei bacteremia, 60% had pancreaticobiliary cancer, with the biliary tract as the most common source. Resistance did not develop in any of the 10 patients treated with third-generation cephalosporins.

Fusarium species are important opportunistic fungal pathogens. Diabetic foot infection (DFI) involves diverse causative pathogens however, the potential for fungal etiologies is often overlooked. We describe a case of DFI following foot trauma. Despite prior broad-spectrum antimicrobial therapy, the wound failed to heal and presented persistent swelling and pain. Microbiological re-evaluation and molecular identification confirmed the causative agent as Fusarium keratoplasticum (F. keratoplasticum), a pathogenic species within Fusarium solani species complex (FSSC). The isolate exhibited high MICs against most antifungals, thus systemic antifungal therapy was withheld. Successful management was achieved through systematic surgical debridement combined with silver-ion dressings, resulting in pathogen eradication and complete wound healing. Currently, F. keratoplasticum infections remain extremely limited, particularly those definitively confirmed to species level. This case broadens the pathogen spectrum of DFI and highlights the need for comprehensive etiologic evaluation in therapy-refractory wounds, offering a non-pharmacological strategy for resistant fungal infections.

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide, driving significant antibiotic use. The gold standard methods like urine culture, are very time consuming and may delay the right treatments at right time. Rapid diagnosis with point-of-care tests (POCTs) have emerged as potential alternatives, offering potential benefits in pathogen identification (ID) and antimicrobial susceptibility testing (AST). The main objective of this review is to evaluate the diagnostic accuracy of the POCTs in view of sensitivity, specificity, and dual assessment of pathogen ID with AST. The literature search was conducted across PubMed, MEDLINE, Europe PMC, and Google Scholar, limited to English-language publications, and covered studies up to April 30, 2025, the date of completion before manuscript submission. The review included diagnostic test accuracy studies, cross-sectional diagnostic validation studies, randomized and non-randomized controlled trials, and prospective comparative studies that enrolled both male and female patients across all age groups in primary care, outpatient, or tertiary healthcare settings with a suspicion of UTI. The comparator in all studies was standard urine culture and sensitivity. The data extraction was done by four investigators independently, rated risk of bias and assessed the quality using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) framework. The assessment of diagnostic test accuracy were analyzed with 95% CI. Fourteen studies were included in the review. Meta-analysis was performed on 12 studies for pathogen ID and 9 studies for AST, yielding pooled sensitivity and specificity estimates for both outcomes. Pooled sensitivity and specificity were 92.2% and 92.7% for pathogen ID, and 92.1% and 89.2% for AST. Time-to-result ranged <1 h to 24 hours. High diagnostic accuracy aids clinical efficacy, though heterogeneity and enactment barriers remain. POCTs have shown potential accuracy for UTI diagnosis and AST, facilitating rapid decisions, but further validation and cost studies remain necessary.

We evaluated the susceptibility of 8,123 Gram-positive bacteria from patients with skin and skin structure infections at 33 US hospitals. Ceftobiprole inhibited 99.8% of Staphylococcus aureus, including 99.5% of methicillin-resistant isolates, at ≤2 mg/L. Ceftobiprole was highly active against β-hemolytic streptococci, coagulase-negative staphylococci, viridans group streptococci, and Enterococcus faecalis isolates.

Serological methods are currently the most widely used approach for diagnosing tularemia. Identifying and evaluating immunoreactive antigens of Francisella tularensis could significantly enhance the development of an advanced diagnostic method for tularemia. This study aimed to assess three F. tularensis recombinant proteins of F. tularensis for their potential application in serodiagnosis. In the present study, three proteins were selected for evaluation. Outer membrane protein A (FopA, FTT0583), a conserved hypothetical protein (FTT0975), and GroEL protein (FTT1696). Genes from F. tularensis subsp. Holarctica LVS NCTC 10857 were cloned and expressed using the pET28a-E. coli BL21 system. The recombinant proteins were analyzed by SDS-PAGE and confirmed via western blot. After purification, immunoblot assays were performed on sera from tularemia patients and healthy controls to detect anti-F. tularensis IgG antibodies. Successful cloning of all three genes was confirmed by PCR, restriction enzyme digestion, and sequencing. The recombinant proteins were effectively expressed and purified. Immunoblotting with sera from tularemia patients showed seroreactivity rates of 36% for FopA, 24% for FTT0975, and 52% for GroEL. The diagnostic values for combination of these proteins were as follows: FopA-FTT0975 (44%), GroEL-FTT0975 (58%), FopA-GroEL (64%), and FopA-GroEL-FTT0975 (66%). No false positives were found in control sera. Although all three recombinant proteins exhibited moderate diagnostic value individually, they demonstrated enhanced performance when combined. Therefore, these proteins are recommended for use alongside other immunogenic proteins in the development of improved diagnostic tests for tularemia.

Background: Efficient monitoring of HIV drug resistance (HIVDR) relies on standardized bioinformatics tools for accurate identification of drug resistance mutations (DRMs). Thus, we sought to compare the concordance of HIV-1 genotypic profiling from sequences analyzed with two commonly-used editing algorithms in low- and middle-income countries (LMICs).

Methods: A laboratory-based comparative study was conducted among treatment-experienced people living with HIV attending the Chantal BIYA International Reference Centre in Yaoundé-Cameroon from October-2022 through July-2023. For each individual, raw data of HIV-1 sequences were analyzed simultaneously using RECall (semi-automated) vs. Exatype (automated) algorithms. Outputs were compared for DRMs, polymorphisms and subtyping between the two algorithms, with significance at p<0.05.

Results: Overall, 221 participants were included (mean-age 32±15 years, 52.5% female). Validation of sequence quality was 70.1% (155/221) by RECall vs. 60.2% (133/221) by Exatype, Ka=0.78 (p<0.0001), indicating a good agreement between both algorithms. Importantly, a perfect concordance (100%) was found in HIV-1 clade inference (CRF02_AG [82/82], A1 [29/29], G [5/5], F2 [5/5] and others [12/12]). Similarly, high concordances were found for the identification of DRMs to protease-inhibitors (99.0%), nucleoside reverse-transcriptase inhibitors (98.0%), non-nucleoside reverse-transcriptase inhibitors (98.6%) and integrase-inhibitors (100.0%). The average turn-around-time was two-folds longer with RECall (5.5±1.7 min) vs. Exatype (2.5±1.1 min); giving a lower efficiency (i.e. validation rate/time) with RECall (12.7) vs. Exatype (24.1).

Conclusions: Semi-automated (RECall) and automated (Exatype) tools showed excellent agreement in detecting HIV-1 clades and DRMs, supporting their interoperability in clinical practice. Following efficiency, Exatype can be considered preferential, while RECall remains a quite suitable alternative for LMICs.

Intestinal diseases markedly impair quality of life, with irritable bowel syndrome (IBS), ulcerative colitis (UC), and Crohn's disease (CD) representing major functional and inflammatory gastrointestinal disorders. This study aimed to determine the prevalence of Dientamoeba fragilis and other intestinal parasites in these conditions and to compare the diagnostic performance of conventional and molecular methods. A total of 80 stool samples were analyzed, including 60 from patients with IBS, UC, or CD and 20 from healthy controls. Samples were examined using direct microscopy, concentration techniques, trichrome staining (TS), and real-time polymerase chain reaction (qPCR), which was applied specifically for the detection of D. fragilis. Overall, parasites were detected in 60% of patients and 15% of controls. Infection rates were 33.3% in CD, 68.8% in UC, and 58.5% in IBS patients. D. fragilis was identified in 18.8% of UC and 22.0% of IBS cases, with significant differences observed between microscopy, TS, and qPCR in detection rates. Blastocystis sp. was found in 21.7% of patients and 5% of controls, with the highest prevalence in UC patients (37.5%). Other detected parasites included Iodamoeba bütschlii, Endolimax nana, Entamoeba coli, Giardia intestinalis, Chilomastix mesnili, Entamoeba spp., and Cystoisospora belli. While direct microscopy showed limited sensitivity, TS improved detection moderately, and qPCR provided the highest sensitivity for D. fragilis. These findings highlight the predominance of D. fragilis in IBS and Blastocystis sp. in UC and underscore the importance of molecular methods for accurate parasitological diagnosis.