International Journal of Microbiology最新文献

Background: Antimicrobial resistance (AMR) is a critical global health threat, with disproportionately high burdens in low- and middle-income countries. In Indonesia, where antimicrobial stewardship initiatives are still developing, local antibiograms are scarce yet crucial to guide evidence-based empirical therapy.

Methods: We conducted a retrospective descriptive study of cumulative antibiogram data from YARSI Hospital, a tertiary care academic hospital in Jakarta, Indonesia, covering January-December 2024. Analysis followed Clinical and Laboratory Standards Institute (CLSI) M39-A4 guidelines and was restricted to the first clinical isolate per species, patient, and specimen type. Susceptibility data were stratified by Gram classification, specimen source, and care setting, with semester-wise comparisons (January-June vs. July-December).

Results: Among 1782 clinical specimens, Klebsiella pneumoniae predominated among Gram-negative isolates, exhibiting high multidrug resistance with ≤ 20% susceptibility to third-generation cephalosporins, particularly in blood and ICU samples. Acinetobacter baumannii, the leading respiratory and ICU isolate, retained susceptibility only to amikacin (15%) and trimethoprim-sulfamethoxazole (25%). Escherichia coli from urine remained susceptible to ceftazidime (78%), cefepime (81%), meropenem (95%), and amikacin (93%). Gram-positive isolates, including Staphylococcus epidermidis and Enterococcus faecalis, were largely susceptible to vancomycin and linezolid, although frequent coagulase-negative staphylococcal bacteremia suggested challenges in aseptic technique.

Conclusion: The persistence of multidrug-resistant K. pneumoniae and A. baumannii highlights the urgent need for targeted antimicrobial stewardship in Indonesian tertiary hospitals. Routine, stratified antibiogram reporting is essential to guide empirical therapy, inform policy, and curb the progression of AMR.

Developing effective antimicrobial treatments for face masks is an attractive aspect of medical applications. Copper nanoparticle (CuNP)-infused medical masks are preferred due to their superior antibacterial properties. However, producing CuNPs presents challenges in antimicrobial applications. This study introduces a green synthesis method using Smyrnium cordifolium extract, offering an eco-friendly approach to CuNP production. A central composite design (CCD) was employed to optimize the biosynthesis of CuNPs, considering the effects of copper sulfate concentration, plant extract volume, pH, and temperature. The CuNPs were characterized using FE-SEM, TEM, EDX, FTIR, zeta potential, and DLS techniques. The dip-coating method was used to decorate CuNPs onto the melt-blown layer of medical masks. The antibacterial efficacy of the coated masks against Acinetobacter baumannii and Staphylococcus aureus was evaluated using the colony count method. The green fabrication of CuNPs was carefully enhanced by employing 14.7 mM CuSO₄ and 14.7 mL of Smyrnium cordifolium extract, adjusting the pH to 6.8, and maintaining a temperature of 54°C. FE-SEM analysis revealed that the CuNPs had a nanostructure size ranging from 31 to 57 nm. Mask decoration with 1.5% CuNPs demonstrated the highest antibacterial activity. Antibacterial efficacy exceeded 85% against Acinetobacter baumannii within 0.25 h. Additionally, antibacterial activity was shown for Staphylococcus aureus with a potency of 85% after 2 h. These findings confirm the potential of biosynthesized CuNPs to enhance the antimicrobial properties of medical face masks, contributing to the development of sustainable protective equipment.

The gut microbiota of wild mice exhibits a significant correlation with their environmental adaptability, particularly highlighted by the dominance of Lactobacillus spp. This study evaluated the probiotic traits of Lactobacillus intestinalis Y10, a fecal isolate from Rattus norvegicus, through in vitro assays. The strain demonstrated two-hour survival in acidic conditions (pH 2.5; 72.4% viability) and maintained viability under 0.3% bile salts for 24 h. It also showed high hydrophobicity index (93.80%) and auto-aggregation percentage (81.68%), indicative of superior mucosal adhesion potential. Organic acid-mediated antimicrobial and antibiofilm activity of strain Y10 against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus subsp. aureus exhibited concentration dependence. Antibiotic susceptibility profiling identified sensitivity to cell wall-targeting agents (penicillin and cephalosporin) but resistant to antibiotics that inhibit nucleic acid synthesis and cytoplasmic membrane function, suggesting the possibility of clinical compatibility with fluoroquinolones or diaminopyrimidines for treatment of specific infections to minimize gut microbiota disruption. These findings position L. intestinalis Y10 as a promising candidate for rodent-specific probiotic applications, combining environmental resilience with pathogen exclusion capabilities. Further in vivo validation and mechanistic studies are required to translate these traits into therapeutic interventions for gastrointestinal dysbiosis.

Silymarin is a natural polyphenol known for its broad range of biological effects, and research conducted in macrophages and mice infected with Mycobacterium tuberculosis have highlighted its potential as a complementary treatment for tuberculosis. Silymarin modulates multiple cellular signaling pathways associated with various aspects of the immune response. However, its effect on the control of M. tuberculosis infection in pulmonary epithelial cells is still not well understood. In this study, we evaluated the effect of silymarin on the infection control and immune response of A549 pulmonary epithelial cells infected with M. tuberculosis H37Ra. Our findings showed that the A549 cell line was more sensitive to the cytotoxic effects of silymarin, particularly to silibinin. The treatment of A549 cells with a dose of 50 μM favors the control of infection caused by M. tuberculosis H37Ra. The treatment resulted in a reduction of the inflammatory response, which correlates with lower activation of pNF-κB. Additionally, the treatment affects the expression of miRNAs that may target several genes involved in immune response signaling pathways, including the MAPK signaling pathway, the apoptosis pathway, the JAK-STAT signaling pathway, the TNF signaling pathway, and the NF-κB signaling pathway. Our results suggest that silymarin treatment contributes to the control of infection and protects the pulmonary epithelium by decreasing the inflammatory response.

The high mortality and morbidity resulting from diarrhoeal cases worldwide are associated with the increasing incidence of antimicrobial resistance (AMR) and represent a serious public health concern. Cattle are a major reservoir of AMR organisms, and faecal shedding may facilitate their transmission into the food chain. This study examined the pathotype, biofilm, virulome and resistome profiles of bacteria isolated from cattle faeces using whole genome sequencing (WGS). Asymptomatic cattle faecal samples (n = 269) were analysed, and three isolates identified as multidrug-resistant and biofilm-forming bacteria were sequenced. In this study, we successfully isolated bacteria from cattle faecal samples, and the isolates DEC_NWU, DVC_NWU and DSS_NWU were phenotypically confirmed as multidrug-resistant and strong biofilm formers. WGS analysis confirmed DEC_NWU, DVC_NWU and DSS_NWU to have genome lengths of 4,803,571, 4,499,945 and 5,374,783 bp, respectively. The Genome Taxonomy Database (GTDB) confirmed that DEC_NWU, DVC_NWU and DSS_NWU are E. coli, V. cholerae and S. enterica, respectively. Also, the genetic nexus of the isolates with other species confirmed that DEC_NWU, DVC_NWU and DSS_NWU were related to E. coli O104:H4 (88%), V. cholerae O1 (100%) and S. enterica serovar Typhimurium (100%), respectively. In addition, PathogenFinder classified the isolates as human pathogens. Furthermore, virulence factors such as adherence, iron uptake, invasion, toxin and secretion system were detected in the genomes of DEC_NWU, DVC_NWU and DSS_NWU. The DSS_NWU genome had the highest number of virulence genes (65), compared to DVC_NWU (29) and DEC_NWU (40). Notably, DEC_NWU, DVC_NWU and DSS_NWU each harboured several resistance genes. This study established that asymptomatic cattle carry human pathogens, which harbour a repertoire of virulome and resistome.

Background: Pharyngitis is inflammation of the oropharynx primarily caused by Streptococcus pyogenes. S. pyogenes is a Gram-positive, catalase-negative, β-hemolytic, bacitracin-sensitive bacterium. Group A streptococci (GAS) pharyngitis causes the most outpatient visits and frequent antibiotic prescriptions among children. In the study area, there is a lack of studies on the prevalence and antimicrobial susceptibility pattern of GAS pharyngitis.

Objective: To determine the throat swab culture positivity rate, antimicrobial resistance patterns, and associated factors of S. pyogenes infection among children with acute pharyngitis attending Jigjiga University Sheik Hassan Yebere Referral Hospital from February 8 to August 4, 2024, in Jigjiga, Ethiopia.

Methodology: A cross-sectional study was conducted among 468 participants recruited from the hospital pediatrics department through a convenience sampling method. Sociodemographic and clinical data were collected from the study participants using a structured questionnaire. Oropharyngeal swabs were collected and processed to identify the S. pyogenes pathogen using the conventional culture, followed by specific biochemical tests according to standard operating procedures. The Kirby-Bauer disk diffusion method was implemented for antimicrobial susceptibility testing. Data were entered into EpiData and then exported to SPSS Version 20, and the analysis was done.

Result: Among the 468 study participants, 269 (57.5%) were males, and the mean age of the participants was 4, with a standard deviation (SD) of 3.6. The prevalence of S. pyogenes infection among children with pharyngitis attending the hospital was 14.3% (95% CI: 11.3-17.8). The presence of household smoking (AOR = 2.67; 95% CI: 1.47-4.89) and tonsillar swelling (AOR = 2.1; 95% CI: 1.03-4.19) were significantly associated with S. pyogenes infection. The isolated organisms showed resistance to tetracycline (17.9%), azithromycin (11.9%), chloramphenicol (10.4%), and clindamycin (9%).

Conclusion: The findings indicate that the prevalence of S. pyogenes infection in this study was slightly higher than that in comparable studies. The presence of household smokers and of tonsillar swelling was significantly associated with the positive S. pyogenes diagnosis.

Abstract: Cutibacterium acnes is an anaerobic bacterium isolated from prosthetic joint infections (PJI), an infection which does not induce clinically relevant symptoms for patients without fever, serum inflammatory markers and has a very indolent course. C. acnes species participates in the balance of skin microbiota but is also responsible for infections; this species is regarded as an opportunistic pathogen or pathobiont. The aim of this study was to determine the existence of a correlation between clinical infectious characteristics of patients and C. acnes clinical strains behaviors. They were evaluated through the determination of bacterial internalization, persistence rate into osteoblast-like cells, and biofilm formation capacity before interaction and for internalized bacteria. This phenomenon could play a role in infections without having yet been observed in vivo. A total of 28 clinical strains were isolated and analyzed from patients with C. acnes PJI. Similar infectious clinical characteristics were observed among the PJI patients, whereas the associated clinical strains have various and heterogeneous behaviors in the in vitro assay of this study. Most of the tested C. acnes strains (75%) were internalized into osteoblast-like cells with a higher rate of C. acnes strains with phylotype IA1 than other phylotypes (IB and II). High internalization rates of C. acnes in osteoblast-like cells seemed to be associated with strains isolated from patients with no local inflammatory symptoms, especially articular stiffness profile. All the strains were able to form biofilm, and internalization into osteoblast-like cells modified the capacity of clinical strains to form biofilm significantly for seven clinical strains (25%), associated with the presence of a high level of polymorphonuclear leukocytes-patient blood with PJI from whom these strains were isolated. In our cohort, the persistence rate of C. acnes strains in osteoblast cells is less important for strains isolated from patients with tobacco use. This study raises the hypothesis that the interaction between bone environment, host, and strain modulates C. acnes ability to stimulate inflammatory symptoms in patients with C. acnes PJI.

Trial registration: ClinicalTrials.gov identifier: NCT03950063.

This review summarizes the research progress on inhibitors of lumpy skin disease virus (LSDV), focusing on its biological characteristics and key proteins involved in the viral replication cycle. It compiles various inhibitors (direct-acting poxvirus inhibitors and host-directed poxvirus inhibitors) against poxviruses, their mechanisms of action, and potential targets, aiming to provide references for the development of LSDV inhibitors. Additionally, the application of computer-aided drug design methods in anti-LSDV inhibitor research is discussed, offering insights from the perspective of virtual screening to facilitate the discovery of novel antiviral agents.

As global industrialization advances and land-based resources decline, deep-sea resource development is becoming increasingly vital. The deep sea is rich in minerals such as polymetallic nodules, polymetallic sulfides, and cobalt-rich crust. However, deep-sea ecosystems and geochemical cycles can be severely impacted by extensive mineral mining. The extraction, collection, hoisting, washing, offshore processing, and transportation of minerals will impact the seabed, the water column, and the surface environment of the original marine area to varying degrees. Deep-sea ecosystems are particularly fragile, with scarce sources of matter and energy, making the impacts of deep-sea mining far more severe than anticipated until now. A comprehensive assessment of the ecological impacts associated with deep-sea mineral extraction is essential to ensure a sustainable and responsible development of deep-sea resources. Quantitative assessments indicate that sediment plumes generated by mining can disperse over 5-10 km from the operation site, while benthic community recovery may require several decades to centuries, underscoring the long-term ecological risks involved. These assessments lay the basis for effective systems and standards for sustainable mining, environmental monitoring, and governance. This review summarizes the current state of deep-sea mineral extraction and utilization, analyzes the ecological and environmental consequences of mining activities, and discusses emerging technologies and innovative approaches for recovering resources in the deep ocean. This study is aimed at serving as a scientific reference for researchers and policymakers, contributing to the development of international frameworks and standards for the sustainable exploitation of deep-sea minerals.

Background: Campylobacter jejuni, a major foodborne and zoonotic pathogen linked to poultry, is showing rising resistance to last-resort antimicrobials like oxazolidinones and phenicols. Such resistance threatens both animal and human health. Its ability to acquire genes from gram-positive bacteria highlights the need for surveillance in avian reservoirs.

Aim: This study aimed to characterize oxazolidinone- and phenicol-resistance determinants among 197 C. jejuni isolates from avian sources in Tunisia.

Methods: Isolates were studied by determining their antimicrobial susceptibility by disk diffusion method, and resistant isolates were screened by PCR for fexA, fexB, floR, RE-cmeABC, cfr, and optrA genes.

Results: Resistance rates were alarmingly high (57.6%-100%) across multiple antibiotic classes, and the majority were multidrug resistant. Among 155 (78.7%) chloramphenicol-resistant isolates, the prevalence of optrA, cfr, fexA, floR, RE-cmeABC, and fexB was 85%, 55%, 75%, 46%, 42%, and 22%, respectively, with most isolates harboring multiple genes. Phylogenetic analysis revealed close relatedness among Tunisian optrA and fexB sequences and similarities with those reported in Enterococcus spp., suggesting intergenus gene exchange.

Conclusion: This study reports for the first time the detection of fexB gene and its co-occurrence with optrA in C. jejuni, highlighting its potential role as a reservoir of transferable resistance genes. These findings underscore the urgent need for enhanced surveillance and antimicrobial stewardship within a One Health framework.