Search Results (1,088)

Background/Objective:Staphylococcus aureus produces staphyloferrin A (Sfna) siderophores to sequester host iron during infection and rapid cell proliferation We examined drug susceptibility, siderophore production, and genome sequencing of clinical isolates of S. aureus. Methods: A total of 100 specimens, including pus, sputum, hemoculture, urine, tissue, fluid, and skin scrap specimens, were grown in iron-deprived Luria broth agar. The isolates were investigated for spectral signature using MALDI–TOF/MS, while antibiotic susceptibility and siderophore content were assessed using the chrome azurol S method. Whole genome and partial 16S rRNA DNA sequences were employed, and VITEK/MS revealed specific spectra. Results: Clindamycin, erythromycin, gentamicin, linezolid, moxifloxacin, oxacillin, trimethoprim/sulfamethoxazole, and vancomycin (100%) were the most common antibiotics to which the S. aureus isolates were susceptible. Sfna was not detectable in fluid and skin scrap isolates, which were encoded by sfnaB, sfnaD, and sfnaB/sfnaD genes. However, they were detectable in pus (73.8%), sputum (85.3%), hemoculture (50.0%), and urine (85.7%) isolates. The aureus subspecies, JKD6159, SA268, and MN8, were found to be 72.73% according to genome sequencing. Conclusion: most staphylococci in the isolates, including S. aureus JKD6159, SA268, and MN8, were sensitive to antibiotics and were detected by MALDI–TOF/MS, resulting in the production of Sfna encoded by sfna genes. Full article

Background/Objectives: Livestock species, particularly dairy animals, can serve as important reservoirs of E. coli, carrying antibiotic resistance and virulence genes under constant selective pressure and their spread in the environment. In this study, we performed the pathogenomic analysis of seven multidrug resistant (MDR) E. coli strains carrying efflux-associated and virulence genes from the dairy farm environment in Xinjiang Province, China. Methods: First, we processed the samples using standard microbiological techniques followed by species identification with MALDI-TOF MS. Then, we performed whole genome sequencing (WGS) on the Illumina NovaSeq PE150 platform and conducted pathogenomic analysis using multiple bioinformatics tools. Results: WGS analysis revealed that the E. coli strains harbored diverse antibiotic efflux-associated genes, including conferring resistance to fluoroquinolones, aminoglycosides, aminocoumarins, macrolides, peptides, phosphonic acid, nitroimidazole, tetracyclines, disinfectants/antiseptics, and multidrug resistance. The phylogenetic analysis classified seven E. coli strains into B1 (n = 4), C (n = 2), and F (n = 1) phylogroups. PathogenFinder predicted all E. coli strains as potential human pathogens belonging to distinct serotypes and carrying broad virulence genes (ranging from 12 to 27), including the Shiga toxin-producing gene (stx1, n = 1). However, we found that a few of the virulence genes were associated with prophages and genomic islands in the E. coli strains. Moreover, all E. coli strains carried a diverse bacterial secretion systems and biofilm-associated genes. Conclusions: The present study highlights the need for large-scale genomic surveillance of antibiotic-resistant bacteria in dairy farm environments to identify AMR reservoir spillover and pathogenic risks to humans and design targeted interventions to further stop their spread under a One Health framework. Full article

Yeast bloodstream infections lead to high mortality and morbidity and are mostly observed in immunocompromised patients. In Africa, only a few studies have characterized clinical yeasts. To increase insight into yeast resistance and transmission in Africa, we identified various yeasts from Alexandria, Egypt and performed antifungal susceptibility testing (AFST) and genotyping. A total of 1307 single isolates from unique patients, recovered from different anatomical sites including the bloodstream, retrieved from a reference laboratory in Alexandria, Egypt were studied. All isolates were identified with MALDI-TOF MS, while some were initially identified with a Vitek 2 Compact system. Short tandem repeat (STR) genotyping was performed for the most common species, and AFST was performed with microbroth dilution. Among bloodstream isolates (n = 71), C. albicans was the most common etiological agent, followed by C. tropicalis and C. parapsilosis. Comparison of yeast identification methods demonstrated that 22% of isolates were incorrectly identified with the Vitek 2 Compact system compared to MALDI-TOF MS. Multiple rare yeasts showed reduced antifungal susceptibility. STR genotyping demonstrated potential events of nosocomial transmission with N. glabratus and C. parapsilosis. Moreover, an azole-resistant C. tropicalis clade identified earlier in Alexandria was still present. To conclude, clinical yeasts in Alexandria, Egypt, are overall susceptible common species. Full article

Monitoring Campylobacter and antimicrobial resistance is critical, as its presence in the food chain, particularly in poultry, represents a serious threat to public health. However, despite its significant impact, this bacterium remains largely underestimated and under-surveilled in many countries, including Morocco. The current study aims to understand the occurrence of Campylobacter spp. in different poultry production systems, highlighting the importance of continuously monitoring antimicrobial susceptibility in these bacteria. For this purpose, 300 poultry samples were collected from a slaughterhouse and 254 from traditional markets in the Rabat-Salé-Kénitra region. The research on Campylobacter was performed according to the standard ISO10272-1(2017), and the confirmation of Campylobacter species was carried out using MALDI-TOF mass spectrometry. Additionally, the disk diffusion method was employed to assess antimicrobial susceptibility, and conventional PCR was utilized to detect the presence of the tet(O) gene in tetracycline-resistant strains. Out of 554 samples collected, 159 (28.7%) tested positive for Campylobacter, of which 84% were identified as Campylobacter coli and 16% as Campylobacter jejuni. Moreover, the results revealed a notably higher detection of Campylobacter in traditional markets (41.33%) than in slaughterhouses (19.85%). Additionally, it was more prevalent in chicken samples (35.37%) than in turkey samples (22.02%). Campylobacter resistance to antimicrobials revealed a resistance rate of 99% to ciprofloxacin, 73% to ampicillin, 82% to tetracycline, 29% to erythromycin, and 0% to gentamicin, as well as to the association of amoxicillin and clavulanic acid. Among the strains with a phenotypic resistance profile to tetracycline, 80% carried the tet(O) gene. The results provide an overview of the current state of antibiotic resistance in Campylobacter in Morocco. They underline the urgent need for the prudent use of antimicrobials and may encourage further research into the development of new antimicrobial agents. They also highlight the importance of raising awareness of the risk of carcass contamination Full article

This study aimed to evaluate the virulence of 36 clinical isolates estimated as blood culture contaminants (BCCs). MALDI-TOF MS classified all isolates as coagulase-negative staphylococci (CoNS) with the highest percentage of S. epidermidis (77.78%). All tested strains formed biofilms with greater ability at room temperature than 37 °C. CoNS were sensitive to vancomycin (0% resistance) and had relatively low resistance to linezolid and rifampicin (8.33 and 22.22% resistance). The highest resistance was observed for penicillin (94.44%). Moreover, we observed the transfer of antibiotic resistance genes from the tested CoNS to S. aureus and even to E. coli, although with lower efficiency. CoNS in planktonic form were completely combated by antiseptics after 10 and 60 s exposition, and activity against biofilms was time-dependent. The complete elimination of biofilms was observed after a 180 s exposure to Kodan and CITROclorex, and this exposure to Rivanol and Octenidyne showed still viable cells (>0.9 log CFU/mL). Our findings showed that a careful selection of antiseptics and extending the exposure time before blood collection can reduce the occurrence of blood culture contamination. However, our most important finding is the indication that CoNS naturally occurring on human skin and mucous membranes exhibit antibiotic resistance, and what is more, determinants of antibiotic resistance are transferred to both closely related Gram-positive bacteria and phylogenetically distant Gram-negative bacteria. Thus, our findings shed new light on CoNS—they indicate the necessity of their control due to the effective transfer of mobile genetic elements harboring antibiotic resistance genes, which may contribute to the spread of resistance genes and deepening the antibiotic crisis. Full article

The identification of filamentous fungi by matrix-assisted laser desorption/ionization–time of flight mass spectrometry (MALDI–TOF MS) represents a challenge due to their complex taxonomy and the lack of comprehensive databases. The aim of this study was to evaluate the current status of available MALDI–TOF MS databases for the identification of dermatophytes, including commercial, in-house, and web-based databases. We collected 289 dermatophyte strains from different centers and analyzed them using four databases and a combination of them. The combination of commercial and in-house databases was shown to improve the identification rate and accuracy at the species level. For Trichophyton rubrum, the concordance among all databases was above 90.0%. For the T. mentagrophytes group, correct identification at the species level ranged from 30.0 to 78.9%, depending on the database, and showed very low agreement among them. The addition of the novel species T. japonicum to our in-house database resulted in the successful identification of this species. On the other hand, T. interdigitale and T. tonsurans were the species most frequently misidentified by MALDI–TOF MS. Through deep spectra analysis of both species, up to 29 protein peaks were found to be suitable for their differentiation, demonstrating the potential of peak analysis in differentiating closely related species. In conclusion, improvements of the databases with new strains resulted in increased identification accuracy at the species level. This, combined with peak analysis, could improve the overall identification of dermatophytes by MALDI–TOF MS in clinical laboratories. Full article

Milk’s biological origin determination, including its adulteration and authenticity, presents serious limitations, highlighting the need for innovative advanced solutions. The utilisation of proteomic technologies combined with personalised algorithms creates great potential for a more comprehensive approach to analysing milk samples effectively. The current study presents an innovative approach utilising proteomics and neural networks to classify and distinguish bovine, ovine and caprine milk samples by employing advanced machine learning techniques; we developed a precise and reliable model capable of distinguishing the unique mass spectral signatures associated with each species. Our dataset includes a diverse range of mass spectra collected from milk samples after MALDI-TOF MS (Matrix-assisted laser desorption/ionization-time of flight mass spectrometry) analysis, which were used to train, validate, and test the neural network model. The results indicate a high level of accuracy in species identification, underscoring the model’s potential applications in dairy product authentication, quality assurance, and food safety. The current research offers a significant contribution to agricultural science, providing a cutting-edge method for species-specific classification through mass spectrometry. The dataset comprises 648, 1554, and 2392 spectra, represented by 16,018, 38,394, and 55,055 eight-dimensional vectors from bovine, caprine, and ovine milk, respectively. Full article

Background. Blastocystis spp. is a common protozoan found in the gastrointestinal tract, typically existing as a non-pathogenic organism in humans and other animals. However, it can become pathogenic when the immune system is compromised due to bacterial, viral, fungal, or other parasitic infections, as well as systemic conditions, leading to symptomatic blastocystosis. Methods. Fecal samples were collected from patients at the University Hospital of Campania “Luigi Vanvitelli” and Cotugno Hospital in Naples. Among these samples, those that tested positive for Blastocystis spp. and were associated with other microbial infections were further analyzed. Bacterial co-infections were identified using immunochromatographic tests (ICTs) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Viral infections were detected using chemiluminescent immunoassay (CLIA), while fungal infections were diagnosed through microscopic examination and molecular biology techniques. Additionally, co-infections with other parasites were identified through microscopic analysis after Ridley’s concentration and Giemsa staining (O&P). Results. Out of the 2050 stool samples collected, 121 were positive for Blastocystis spp., of which 75 were associated with other infections. We identified the vacuolar form in patients co-infected with bacteria (n = 22), viruses (n = 30), fungi (n = 3), and other parasites (n = 20). Conclusions. Our findings indicated a higher incidence of the vacuolar form of Blastocystis spp. in symptomatic and immunocompromised patients, suggesting that a weakened immune system may increase the risk of contracting Blastocystis and other microbial infections. Full article

Objectives: The aim of this scoping review was to delineate the current role and possible applications of proteomics in personalized breast cancer diagnostic evaluation and treatment. Methods: A comprehensive search in PubMed/MEDLINE and Scopus/EMBASE was conducted, according to the PRISMA–ScR guidelines. Inclusion criteria: proteomic studies of specimens from breast cancer patients, clinically relevant studies and clinical studies. Exclusion criteria: in silico, in vitro and studies in animal models, review articles, case reports, case series, comments, editorials, and articles in language other than English. The study protocol was registered in the Open Science Framework. Results: In total, 1093 records were identified, 170 papers were retrieved and 140 studies were selected for data extraction. Data analysis and synthesis of evidence showed that most proteomic analyses were conducted in breast tumor specimens (n = 77), followed by blood samples (n = 48), and less frequently in other biologic material taken from breast cancer patients (n = 19). The most commonly used methods were liquid chromatography–tandem mass spectrometry (LC–MS/MS), followed by Matrix-assisted laser desorption/ionization-time of flight (MALDI–TOF), Surface-Enhanced Laser Desorption/Ionization Time-of-Flight (SELDI–TOF) and Reverse Phase Protein Arrays (RPPA). Conclusions: The present review provides a thorough map of the published literature reporting clinically relevant results yielded from proteomic studies in various biological samples from different subgroups of breast cancer patients. This analysis shows that, although proteomic methods are not currently used in everyday practice to guide clinical decision-making, nevertheless numerous proteins identified by proteomics could be used as biomarkers for personalized diagnostic evaluation and treatment of breast cancer patients. Full article

Background: Superficial candidiasis (SC) is widespread in humans worldwide. This study aimed to evaluate species distribution patterns and antifungal susceptibility through cluster analysis. Methods: A total of 180 Candida strains isolated from skin and nail samples of 1593 examined patients with suspected superficial fungal infection were identified by Matrix-assisted laser desorption in ionization-time of flight mass spectrometry (MALDI-TOF MS; Zybio EXS2600, China). Antifungal susceptibility was assessed using the commercial Integral System YEASTS Plus test (ISYPT; Liofilchem^®, Italy). Agglomerative hierarchical cluster analysis was used to analyze species distribution and susceptibility. Results: Candida parapsilosis (44.4%) and C. albicans (40%) were the most prevalent causative agents of SC. Cluster analysis established two defined clusters. Cluster 1 (121 isolates) showed a statistically significant difference compared to Cluster 2 (54 isolates) in species distribution (C. albicans was dominant in the first and C. parapsilosis in the second cluster) as well as in susceptibility to ECN (p ≤ 0.001), KCA (p = 0.030), CLO (p ≤ 0.001), MCZ (p ≤ 0.001), ITZ (p ≤ 0.001), and FLU (p ≤ 0.006). Conclusion: The fact that one-third of isolates exhibited low sensitivity to antifungals highlights the need for a new approach in SC treatment, emphasizing the importance of mycological analyses, including in vitro testing of antifungal effectiveness. Full article

Antimicrobial resistance is a growing global threat, with surveillance providing essential information to control its spread and support rational treatment strategies. Klebsiella pneumoniae, a member of the Gram-negative Enterobacteriaceae family, frequently develops resistance mechanisms. This study analyzed 195 rectal swabs from companion and stray dogs in Santiago and São Nicolau (Cape Verde) and São Tomé and Príncipe, sampled during a neutering and deworming campaign conducted by Veterinary Without Borders Portugal, to detect extended-spectrum β-lactamase (ESBL)-producing bacteria. Samples were enriched and then cultured on ChromID^® ESBL agar, and resulting isolates were identified via MALDI-TOF MS. A total of 35 K. pneumoniae isolates were identified, of which 32 were confirmed as ESBL producers. Antimicrobial susceptibility testing showed 100% resistance to aztreonam, cefotaxime, cefpodoxime, and ceftaroline, and high resistance to cefepime (93.8%), ciprofloxacin (93.8%), and trimethoprim/sulfamethoxazole (90.6%). All isolates were considered multidrug-resistant but remained susceptible to cefoxitin, imipenem, and meropenem. The genes bla_CTX-M, bla_SHV, and bla_TEM were present in 96.9%, 65.6%, and 56.3% of the isolates, respectively. DNA fingerprinting revealed seven clusters, suggesting genetic diversity and strain dissemination across locations. These findings highlight the role of dogs as vectors for antimicrobial resistance dissemination, underscoring the need for continuous surveillance in both veterinary and human medicine. Full article

Phytopathogenic fungi are important causative agents of many plant diseases, resulting in substantial economic losses in agriculture. Proteomics has become one of the most relevant high-throughput technologies, and current advances in proteomic methodologies have been helpful in obtaining massive biological information about several organisms. This review outlines recent advances in mass spectrometry-based proteomics applied to the study of phytopathogenic fungi, including analytical platforms such as LC-MS/MS and MALDI-TOF, as well as quantitative strategies including TMT, iTRAQ, and label-free quantification. Key findings are presented from studies exploring infection-related protein expression, virulence-associated factors, post-translational modifications, and fungal adaptation to chemical fungicides, antimicrobial peptides, and biological control agents. Proteomic analyses have also elucidated mechanisms of resistance, oxidative stress response, and metabolic disruption following exposure to natural products, including essential oils and volatile organic compounds. The proteomic approach enables a comprehensive understanding of fungal biology by identifying proteins related to pathogenicity, stress adaptation, and antifungal resistance, while also facilitating the discovery of molecular targets and natural compounds for the development of sustainable antifungal strategies that reduce risks to human health and the environment. Full article

Identification of mycobacterial infections for both Mycobacterium tuberculosis and non-tuberculosis mycobacteria is important for effective patient care. Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is a promising tool that is used in many clinical laboratories for the identification of bacteria and yeast. This study evaluates the impact of growth media on the performance of the MALDI Biotyper^® MBT smart MS for mycobacteria identification. Increased rates of identification, particularly in non-rapid growers and pigment producers, and higher confidence scores were generated in mycobacteria isolated from solid agar, rather than liquid broth. Testing each isolate in triplicate can increase yield of detection. Using the Bruker MBT Mycobacteria Kit to process our samples for testing on the Bruker MALDI Biotyper^® instrument generated precise and accurate mycobacteria identification. These findings emphasize the importance of optimizing mycobacterial specimen processing workflows to include appropriate culture media, which can enhance mycobacterial identification and improve diagnostic accuracy. Full article

Background/Objectives: Two of the microvascular complications in type 2 diabetes (T2D) are diabetic retinopathy (DR), which is the most common cause of non-traumatic blindness, and diabetic kidney disease (DKD); the latter generally requires renal replacement therapy. The aim of the present study was to determine the frequency of polymorphisms of Tumor Necrosis Factor-α, interleukin-6, and interleukin-10 (TNF-α, IL-10, and IL-6), as well as to describe the clinical and laboratory characteristics of T2D association with these microvascular complications. Methods: This study included 203 patients with T2D, of which 102 had microvascular complications: 95 with DR, 50 with DKD, and 15 with diabetic neuropathy (the latter were not included in the statistical analysis); those with T2D without confirmed microvascular complications were considered as controls. Clinical and laboratory data were collected from the patient’s medical records. Polymorphism typing of TNF-α rs361525 and rs1800629 and IL-10 rs1800872 and rs1800871 were obtained using MALDI-TOF MS. IL-10 rs1800896 and IL-6 rs1800795 were typed using a quantitative real-time polymerase chain reaction. Results: The results of age, HbA1c, fasting glucose, and arterial hypertension are significantly associated in every group. The TNF-α rs1800629A allele and TNF-α rs1800629G/A genotype were associated with microvascular complications and DR. For IL-10-rs1800896, all the models were associated in DKD. The TNF-α rs361525-rs1800629GA haplotype was associated with microvascular complications and DR, while the IL-10 haplotype, rs1800872-rs1800871-rs1800896 GGC, showed susceptibility in every group. Conclusions: Our results show the contributions of the variants of these cytokines to these microvascular complications, but more studies are required to reach relevant conclusions. Full article

The goal of the present study was to analyze Acinetobacter baumannii strains isolated from hospitalized patients in the period of the COVID-19 pandemic by phenotypic and molecular methods and evaluate their antimicrobial resistance patterns and biofilm production. Forty-seven strains were isolated in 2021–2022 from a hospital in Brazil, and were identified by VITEK^®2, MALDI-TOF/MS (VITEK MS^® and MALDI Biotyper^®), and 16S rRNA sequencing. Fourier-transform infrared (FTIR) spectroscopy was applied for typing and antimicrobial susceptibility testing (AST). In addition, biofilm formation and disinfectant tolerance tests were used. All methods accurately identified all the A. baumannii strains. FTIR typing identified 23 different profiles and 11 clusters, as well as differentiated between the strains from patients with and without COVID-19. Most strains exhibited resistance to the drugs tested, 91.5% of the strains were classified as XDR, 6.4% of the strains were MDR and only 1 strain was classified as non-MDR. Over half of the strains (n = 27, 57.4%) produced biofilms on polystyrene. Sodium hypochlorite (1.0%/15 min) was the best option for effective disinfection. Overall, this study will lay the foundation for further research on effective cleaning protocols for the eradication of A. baumannii biofilms, as well as the use of FTIR for pathogen surveillance in healthcare settings. Full article