The research, published in BMC Infectious Diseases by Hamed Tabasizadeh, Babak Pourakbari, Setareh Mamishi, and colleagues at Tehran University of Medical Sciences, followed 723 children younger than 18 years who carried central venous catheters at the Children’s Medical Center in Tehran between 2021 and 2024. The team combed through four years of routinely collected clinical records, laboratory results, and microbiology reports to answer several intertwined questions: which children were most likely to develop a central line-associated bloodstream infection, which infected children were most likely to die, which organisms were responsible, how quickly blood cultures turned negative after treatment began, and how often the culprit microbes resisted multiple antibiotics at once.

The headline numbers are stark. Of the 723 eligible children, 182, or 25.2 percent, experienced at least one central line-associated bloodstream infection during their admission. Overall, 128 children in the cohort, or 17.7 percent, died in the hospital. Among the children who did develop a catheter-associated infection, all-cause in-hospital mortality reached 22.0 percent. These figures place the burden of catheter-related sepsis in this setting among the most serious complications in pediatric hospital care, and they underscore why infection prevention teams treat every central line as a potential hazard that must be continuously justified and vigilantly maintained.

Where a child was treated mattered considerably. Using modified Poisson regression, a statistical technique that estimates risk ratios directly rather than odds ratios and performs better when outcomes are common, the researchers adjusted for sex, age group, and admission ward. Compared with children in the pediatric or general intensive care units, those in the cardiac ICU and open-heart ICU faced a 35 percent higher risk of catheter-associated bloodstream infection, with an adjusted risk ratio of 1.35 and a 95 percent confidence interval of 1.00 to 1.82. By contrast, children on transplant and oncology wards had a 43 percent lower risk, with an adjusted risk ratio of 0.57 and a confidence interval of 0.37 to 0.88. The authors suggest that ward-specific surveillance should be a priority, since the drivers of infection, from line-handling practices to the intensity of nursing care, differ substantially across hospital units.

To identify which factors were associated with death among infected children, the team turned to Firth penalized logistic regression, a method designed for situations where events are sparse and conventional models can produce unstable or inflated estimates. The model’s performance was internally assessed using bootstrap validation, in which the analysis is repeated across thousands of resampled datasets to check that the estimates hold up. Two factors stood out. Children whose catheters had been placed in the femoral vein, in the groin, had roughly three times the odds of dying in hospital compared with children whose lines were placed elsewhere, with an adjusted odds ratio of 3.04 and a confidence interval of 1.37 to 6.82. Femoral sites are often chosen in emergencies but are widely regarded as more vulnerable to contamination from the surrounding skin flora. The second mortality signal was thrombocytopenia: every halving of the platelet count raised the odds of death by 51 percent, with an adjusted odds ratio of 1.51 and a confidence interval of 1.20 to 1.94. Falling platelets are a classic laboratory marker of worsening sepsis, reflecting both consumption of clotting factors and the inflammatory storm that severe bloodstream infection unleashes.

The microbiology behind these infections revealed a familiar but troubling cast of characters. Klebsiella species, Gram-negative bacteria notorious for their ability to acquire resistance genes, and Staphylococcus epidermidis, a skin-dwelling organism that becomes a pathogen the moment it finds a plastic surface to colonize, predominated among the bloodstream isolates. This pairing captures the two faces of catheter infection: organisms that exploit the device itself and organisms that thrive in the hospital environment. The distribution of organisms also influenced the clinical course. The time to documented culture negativity, the interval between starting treatment and the first follow-up blood culture showing no growth, differed significantly across organism groups, with a P value of 0.002. In the subgroup analysis, 98 children had Gram-negative infections, 58 had Gram-positive infections, and 16 had fungal infections, and the pace at which their bloodstreams cleared varied accordingly. The authors note that follow-up cultures were not protocolized as part of the study, meaning the timing reflected routine clinical practice rather than a standardized schedule.

Perhaps the most alarming finding concerns antimicrobial resistance. Multidrug resistance, defined as non-susceptibility to at least one agent in three or more antimicrobial classes, was detected in 82.0 percent of assessable children with catheter-associated infections. In practical terms, for every five infected children whose isolates could be tested, four harbored organisms that shrugged off most of the standard antibiotic arsenal. Susceptibility analyses were conducted at the isolate level, with denominators varying by antibiotic because only tested isolates contributed to each percentage, while the primary multidrug-resistance prevalence was estimated at the patient level to avoid inflating the figure by counting repeated isolates from the same child. The supplementary matrices of organism-specific non-susceptibility paint a granular picture of which drugs retained activity against which pathogens, information that clinicians in similar settings can use to guide empiric therapy.

The methodological choices in the study deserve attention because they shape how the findings should be interpreted. Modified Poisson regression with heteroskedasticity-consistent standard errors allowed the team to report adjusted risk ratios that are easier to grasp clinically than odds ratios. Firth’s penalized approach tamed the small-sample instability inherent in mortality modeling among a subset of 182 children. Bootstrap validation provided a check on model performance, assessed through measures such as the area under the receiver operating characteristic curve. The researchers also handled a subtle confounding problem carefully: concurrent mechanical ventilation and inotropic support were recorded as secondary severity markers but kept out of the primary mortality model, because the timing of these interventions relative to infection onset was unavailable and they could just as easily be consequences of infection as causes of death.

As with any single-center retrospective study, there are limits. The data come from one tertiary referral hospital in Tehran, which concentrates the sickest children, including transplant recipients, oncology patients, and post-cardiac-surgery cases, so the infection and mortality proportions may not generalize to community hospitals or to settings with different resistance epidemiology. The requirement for informed consent was waived by the institutional review board because the analysis used routinely collected clinical data, and the study received no specific external funding. The authors declare no competing interests. Still, the consistency of the signals, higher risk in cardiac units, femoral catheters and thrombocytopenia marking mortality, Klebsiella and Staphylococcus epidermidis dominating the isolates, and multidrug resistance in more than four fifths of assessable cases, gives the findings weight.

The study’s conclusions translate into a clear agenda for pediatric hospitals everywhere. Ward-specific surveillance should identify the units where catheter infections cluster. Reliable insertion and maintenance practices, from sterile technique at placement to meticulous dressing changes and hub disinfection, remain the foundation of prevention. Regular review of line necessity, asking every day whether each catheter still earns its place in a child’s vein, shortens exposure and cuts risk. And antimicrobial stewardship programs should be locally informed, built on each hospital’s own susceptibility data rather than generic guidelines, because in a setting where 82 percent of infecting organisms are multidrug resistant, guessing wrong about empiric therapy can be fatal. For the children whose lives depend on central lines, these measures are not bureaucratic box-ticking; they are the difference between a lifeline and a liability.

Subject of Research: Risk factors, mortality, and antimicrobial resistance in central line-associated bloodstream infections among hospitalized children

Article Title: Central line-associated bloodstream infection in hospitalized children: a retrospective cohort study of risk, mortality, and antimicrobial resistance

Article References: Tabasizadeh, H., Pourakbari, B., Sotudeh, M., Sadeghi, R. H., Farahmand, M., & Mamishi, S. (2026). Central line-associated bloodstream infection in hospitalized children: a retrospective cohort study of risk, mortality, and antimicrobial resistance. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14528-4

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14528-4

Keywords: central line-associated bloodstream infection, central venous catheter, pediatrics, sepsis, antimicrobial resistance, multidrug resistance, Klebsiella, Staphylococcus epidermidis, mortality, risk factors, intensive care unit, Iran

The team searched four databases, PubMed, Cochrane, Disbiome and Scopus, from their inception to May 2024, screening 608 records against strict inclusion criteria. Only randomized controlled trials, case-control studies and cohort studies that directly measured microbial diversity or abundance in atopic dermatitis patients relative to healthy controls made the cut. The final synthesis included 23 studies: eight randomized controlled trials, ten case-control studies and five cohort studies. Methodological quality was assessed with validated instruments, including the Cochrane risk-of-bias tool for randomized trials and the Newcastle-Ottawa Scale for observational work, and the meta-analyses followed PRISMA 2020 reporting standards with random-effects modeling to accommodate the expected heterogeneity between studies.

The headline numbers are striking. Across the pooled studies, the bacterial alpha diversity of atopic dermatitis skin was significantly reduced compared with healthy skin, with a standardized mean difference of -1.36 and a p-value below 0.00001. In practical terms, affected skin hosts a far less varied bacterial community, a signature of dysbiosis that has been repeatedly observed but never before quantified with this degree of statistical confidence across study designs. Low diversity is more than a descriptive curiosity: ecosystems dominated by one or few opportunistic species lose the buffering capacity that a rich commensal community provides, leaving the barrier vulnerable to colonization and inflammation.

The second major finding concerns Staphylococcus aureus, the notorious opportunistic pathogen that colonizes the lesions of most moderate-to-severe patients. The meta-analysis found a dramatically increased abundance of S. aureus in atopic dermatitis skin, with a standardized mean difference of 3.49 and a p-value below 0.00001, and the effect was most pronounced in lesional, actively inflamed skin. This aligns with mechanistic work showing that S. aureus exploits epidermal barrier defects to penetrate the skin, where its virulence factors trigger cytokine expression and amplify type 2 inflammation. Earlier longitudinal studies have also shown that S. aureus expansion tracks disease flares and recedes when flares resolve, and that skin pH-dependent S. aureus abundance can predict worsening disease severity, reinforcing the idea that the bacterium is not merely a passenger but an active participant in pathogenesis.

The story of Staphylococcus epidermidis, the skin’s most abundant commensal, proved more nuanced. Across the pooled data, S. epidermidis abundance was elevated overall in atopic dermatitis skin, but the analysis revealed strain-dependent variability that complicates any simple good-bug-versus-bad-bug narrative. Certain S. epidermidis strains are genuinely protective: they ferment glycerin into short-chain fatty acids, inhibit S. aureus biofilm formation, and boost innate immunity through activation of gamma delta T cells and induction of antimicrobial effectors such as perforin-2. Other strains, however, carry deleterious traits. The protease EcpA, produced by some S. epidermidis isolates, can damage the epidermal barrier, and extracellular serine proteases from the species have been shown to elicit type 2-biased immune responses in patients. In other words, the same species can heal or harm depending on which strain dominates, a finding with direct consequences for how live biotherapeutics should be designed and screened.

These microbial shifts sit at the intersection of the two classical pillars of atopic dermatitis. A defective barrier, driven in part by filaggrin loss-of-function and reduced epidermal lipids, creates a dry, alkaline microenvironment that favors S. aureus over commensal staphylococci. Meanwhile, the type 2 immune skew of the disease suppresses the production of antimicrobial peptides, giving the pathogen an additional survival advantage. The result is a self-reinforcing loop: barrier breakdown invites colonization, colonization drives inflammation, and inflammation further degrades the barrier. Interrupting that loop at the microbial node is therefore an attractive strategy, and the review’s authors argue that microbial dysbiosis contributes meaningfully to disease progression rather than simply accompanying it.

Supporting this view, several of the intervention studies included in the synthesis showed that effective treatments also repair the microbiome. Biologic therapies such as dupilumab have been shown to rapidly reduce S. aureus burden and improve stratum corneum hydration, while tralokinumab increased microbial diversity in adults with moderate-to-severe disease in the ECZTRA 1 randomized trial. Emollient-based regimens shifted microflora balance and improved barrier function in children with mild disease, and the skin microbiome of treated patients has been observed to normalize gradually over the course of therapy. Coal tar, one of the oldest eczema remedies, acts partly through aryl hydrocarbon receptor-dependent induction of antimicrobial peptides that reshape the cutaneous bacterial community. Even conventional approaches such as topical corticosteroids and dilute bleach baths have measurable microbiome effects, though not every popular remedy holds up: apple cider vinegar soaks, for instance, failed to alter the bacterial microbiome in a controlled study.

These observations are fueling a growing pipeline of microbiome-targeted therapies. Live biotherapeutics based on selected commensal Staphylococcus strains, topical probiotics and postbiotics, prebiotic formulations that feed protective commensals, and barrier-restoring emollients that indirectly discourage pathogen expansion are all under active investigation. The meta-analysis supports the rationale for such approaches, particularly those that aim to restore microbial balance while simultaneously strengthening the skin barrier. The strain-level complexity of S. epidermidis, however, is a caution: any therapeutic microbe must be selected not just by species but by functional genotype, and manufacturing consistency, colonization stability and long-term safety remain open questions that regulators and developers will need to address.

The study is not without limitations, as the authors acknowledge implicitly through their rigorous quality assessments. Heterogeneity across studies was substantial, reflecting differences in sampling sites, sequencing methods, patient age groups and disease severity, and observational designs cannot fully disentangle cause from consequence in the dysbiosis-inflammation relationship. Subgroup and meta-regression analyses in meta-analyses of this size also carry limited statistical power. Nonetheless, the consistency and magnitude of the two central effects, reduced diversity and S. aureus expansion, across randomized, case-control and cohort designs make microbial dysbiosis one of the most robustly quantified features of atopic dermatitis biology.

For the millions of patients who live with the itch, sleep disruption and infection risk of eczema, the message from this synthesis is ultimately hopeful. The skin microbiome is not a fixed fingerprint but a dynamic, modifiable ecosystem that responds to treatment, and its restoration tracks clinical improvement. As microbiome-targeted interventions mature from concept to clinic, measuring and managing the skin’s bacterial balance may become as routine in dermatology as measuring blood pressure is in cardiology, turning an invisible ecosystem into a concrete therapeutic target for one of the world’s most burdensome chronic diseases.

Subject of Research: Skin microbiome dysbiosis in the pathogenesis of atopic dermatitis

Article Title: The role of skin microbial shifts in the pathogenesis of atopic dermatitis: a systematic review and meta-analysis

Article References: Mohd Noor, N. A., Sulaiman, N. N. Y., Lim, S. M., Ramasamy, K., & Ismail, M. F. (2026). The role of skin microbial shifts in the pathogenesis of atopic dermatitis: a systematic review and meta-analysis. Archives of Dermatological Research, 318(1), Article 513. https://doi.org/10.1007/s00403-026-04990-0

Image Credits: AI Generated

DOI: 10.1007/s00403-026-04990-0

Keywords: atopic dermatitis, skin microbiome, Staphylococcus aureus, Staphylococcus epidermidis, dysbiosis, meta-analysis, eczema, alpha diversity, skin barrier, microbiome-targeted therapy, biotherapeutics, dermatology

The team began with classical natural-products chemistry. Sophoraflavanone G was isolated and purified using chromatographic techniques, and its identity was confirmed by proton nuclear magnetic resonance spectroscopy, the standard method for verifying the hydrogen framework of an organic molecule. Prenylated flavonoids like sophoraflavanone G carry a hydrophobic isoprenoid side chain attached to a flavonoid core, a structural feature long associated with enhanced membrane activity and, consequently, stronger antimicrobial effects than their non-prenylated relatives. That lipophilic appendage is thought to help the molecule insert itself into bacterial lipid bilayers, disturbing membrane integrity and function. The researchers then evaluated both the antibacterial and the anti-biofilm properties of the purified compound across a panel of bacterial strains, including the well-characterized P. aeruginosa strain PAO1 and Staphylococcus epidermidis DSMZ 3270.

Against Gram-positive bacteria, the compound performed impressively. It exhibited potent inhibitory and bactericidal activity against all tested Gram-positive organisms, with Listeria monocytogenes emerging as the most sensitive, inhibited at a minimum inhibitory concentration of just 0.98 micrograms per milliliter. For a plant-derived molecule, sub-microgram-per-milliliter potency is noteworthy and places sophoraflavanone G among the more active flavonoid antibacterials described in the literature. The finding reinforces a pattern that microbiologists have observed repeatedly: prenylated flavonoids tend to be far more effective against bacteria that lack the protective outer membrane characteristic of Gram-negative organisms. That outer membrane, with its tightly packed lipopolysaccharide layer, acts as a molecular sieve that excludes many hydrophobic compounds, including most flavonoids, before they can reach their targets.

The Gram-negative results bore this out in blunt fashion. Sophoraflavanone G showed no meaningful activity against P. aeruginosa in its planktonic, free-swimming form, with a minimum inhibitory concentration exceeding 1000 micrograms per milliliter. In other words, even at the highest concentration tested, the compound could not stop the growth of suspended Pseudomonas cells. This is not a surprise to anyone familiar with the barriers Gram-negative pathogens present, but it matters for the study’s central question: could the compound still do something useful against P. aeruginosa once that pathogen had settled into a biofilm, the matrix-encased community mode in which bacteria are notoriously tolerant of antibiotics?

The answer was nuanced. At low doses, sophoraflavanone G failed to inhibit P. aeruginosa biofilm formation, and it did not enhance the penetration of tobramycin, an aminoglycoside antibiotic commonly deployed against Pseudomonas infections, into the biofilm matrix. Biofilms resist antibiotics through several cooperating mechanisms: an extracellular polymeric substance matrix that physically retards diffusion, metabolic dormancy of cells deep within the community, and the accumulation of resistance determinants. A compound that cannot breach the planktonic outer membrane barrier was unlikely to loosen this fortress on its own at subinhibitory concentrations. The low-dose combination experiments with tobramycin therefore came back essentially negative, a result the authors report transparently rather than overinterpret.

But at a substantially higher concentration of 1 milligram per milliliter, the picture changed. Sophoraflavanone G significantly improved antibiotic penetration into the established P. aeruginosa biofilm. The compound, in other words, appears to act on the biofilm’s permeability barrier in a dose-dependent manner, even though it cannot kill the organism outright. This kind of adjuvant activity, where a molecule with weak intrinsic antibacterial power potentiates a co-administered antibiotic by opening access routes through the biofilm matrix, is an actively pursued strategy in anti-biofilm drug development. The practical caveat is the concentration required: 1 milligram per milliliter is high for systemic therapy, which is why the authors frame this as a proof of principle and call for further development to improve efficacy against Gram-negative pathogens rather than an immediate clinical recommendation.

Where the compound truly shone was against Staphylococcus epidermidis, a Gram-positive coccus that is a leading cause of device-associated infections. S. epidermidis colonizes catheters, prosthetic joints, heart valves, and other implanted materials, encasing itself in biofilms that shield it from both host defenses and antibiotics. The study found that sophoraflavanone G demonstrated strong inhibitory, disruptive, and biofilm-penetrating effects against this organism, with a clear dose-dependent response. It did not merely prevent new biofilm from forming; it also attacked established biofilms and enhanced the penetration of antibiotics into them. For an organism whose pathogenicity depends almost entirely on its ability to form resilient biofilms on medical devices, a molecule that hits biofilm structure and integrity at multiple stages is a genuinely interesting lead.

The contrast between the two organisms encapsulates a central tension in natural-product antimicrobial research. Sophoraflavanone G is, on the evidence of this study, a potent Gram-positive antibacterial and anti-biofilm agent with a plausible secondary role as a biofilm-disrupting adjuvant against Gram-negative pathogens at high concentrations. Its membrane-active chemistry, conferred by the prenyl group, likely explains both strengths: Gram-positive bacteria expose their cytoplasmic membranes directly to the environment, making them vulnerable, while the Gram-negative outer membrane excludes the compound until concentrations are high enough to force some degree of penetration. Understanding this structure-activity relationship could guide medicinal chemists toward derivatives that retain Gram-positive potency while acquiring the ability to cross the Gram-negative barrier, perhaps by tuning lipophilicity or adding metal-chelating or efflux-pump-inhibiting features.

The work also fits into a broader and increasingly urgent context. Antimicrobial resistance, particularly among biofilm-forming pathogens, poses a serious threat to public health, and the World Health Organization has repeatedly flagged carbapenem-resistant P. aeruginosa as a critical-priority pathogen. Biofilm-associated infections are especially intractable because standard susceptibility testing measures activity against planktonic cells, which dramatically underestimates the drug concentrations needed to clear a biofilm on an implanted device. Plant-derived compounds have historically been a rich source of antimicrobial scaffolds, and prenylated flavonoids in particular have attracted attention for their potency and their capacity to act on bacterial membranes and biofilm matrices in ways that complement conventional antibiotics. Studies like this one, which test both planktonic and biofilm modes and include combination experiments with existing drugs, provide exactly the kind of data needed to prioritize candidates for further development.

The authors, led by Niloofar Zanganeh and Vahid Soheili at Mashhad University of Medical Sciences together with Milad Iranshahy and colleagues, are appropriately measured in their conclusions. They underscore the potential of sophoraflavanone G as a candidate for managing Gram-positive and biofilm-associated infections, particularly those involving S. epidermidis, while explicitly highlighting the need for further development to improve its efficacy against Gram-negative pathogens. The study was funded by the Research Council of Mashhad University of Medical Sciences and formed part of a student thesis, illustrating how academic natural-products laboratories continue to feed the antimicrobial pipeline. Whether sophoraflavanone G itself ever reaches the clinic will depend on pharmacokinetics, toxicity, formulation, and the chemistry needed to overcome the Gram-negative barrier, but as a molecular probe it has already delivered a valuable lesson: the same membrane-disrupting feature that makes a flavonoid lethal to staphylococci can, at the right dose, help antibiotics slip past the defenses of one of medicine’s most stubborn Gram-negative adversaries.

Subject of Research: Antibacterial and anti-biofilm activity of the plant-derived prenylated flavonoid sophoraflavanone G against Pseudomonas aeruginosa and Staphylococcus epidermidis

Article Title: Antibacterial evaluation of sophoraflavanone G from Sophora pachycarpa against Pseudomonas aeruginosa and Staphylococcus epidermidis biofilm

Article References: Zanganeh, N., Hatamian, G., Shakeri, A., Bazzaz, B. S. F., Iranshahy, M., & Soheili, V. (2026). Antibacterial evaluation of sophoraflavanone G from Sophora pachycarpa against Pseudomonas aeruginosa and Staphylococcus epidermidis biofilm. BMC Complementary Medicine and Therapies. https://doi.org/10.1186/s12906-026-05564-3

Image Credits: AI Generated

DOI: 10.1186/s12906-026-05564-3

Keywords: sophoraflavanone G, Sophora pachycarpa, biofilm, Pseudomonas aeruginosa, Staphylococcus epidermidis, antimicrobial resistance, prenylated flavonoid, natural products, tobramycin, Listeria monocytogenes, antibiotic adjuvant, Gram-positive bacteria