Abscess Research Articles

43 Etiology of community-acquired bacterial meningitis in children seen in the emergency department in Canada

Abstract Background Bacterial meningitis poses a significant threat to paediatric health, resulting in substantial morbidity and mortality in children. Though previous studies have delineated the causative agents behind community-acquired meningitis, recent vaccination initiatives may have reshaped its underlying etiology. Objectives This study aimed to identify the bacteria responsible for community-acquired bacterial meningitis in children in Canada. Design/Methods This was a retrospective cohort study including children aged 1 day-18 years with confirmed bacterial meningitis, evaluated at a tertiary-care, Canadian emergency department between July 1st 2014 and December 31st 2022. The primary outcome was the pathogen identified. Other variables of interest were mortality, complications, age, sex, and diagnostic method. Medical charts were identified via the hospital’s archives and reviewed by a single co-author. A random sample of 20 (23%) medical charts were independently reviewed by a second co-author to assess inter-rater reliability. We set a target of evaluating at least 50 cases to allow narrow confidence intervals (+/- 13%) for proportions. Results All variables showed excellent inter-rater reliability with Kappa scores and intraclass correlation coefficients higher than 0.60. All 79 eligible cases were included. The main causal agents were Group B Streptococcus (GBS) (n=20; 25%), Streptococcus pneumoniae (n=16; 20%), Neisseria meningitidis (n=16; 20%) and Haemophilus influenzae (n=9; 11%). Etiology exhibited age-dependent variations, with 85% of GBS and 100% of E. coli infections identified in children under two months, while all pneumococcal and Group A Streptococcus cases were in children older than six months. All children infected by S. pneumoniae were vaccinated against pneumococcal infection but the serotype was not covered by vaccination in 7/8 infections. All children with N. meningitidis were either too young to be vaccinated (n=10) or infected by a serotype not covered by the vaccine. Six (7%) patients died and 29 (34%) suffered complications, including hearing impairment (n=5), cerebral ischemia (n=4), seizures (n=4), and subdural abscess (n=3). Fifty-nine bacterias were identified by cerebrospinal fluid culture, 13 by PCR and 7 by both methods. Conclusion GBS is the leading etiology of paediatric community-acquired bacterial meningitis in Canada. Causal agents of bacterial meningitis vary greatly by age. Future studies should work on improving the serotype spectrum of vaccines, prophylaxis in mothers who are GBS carriers, and use of PCR as a diagnostic tool for timely clinical interventions.

Continuous debridement combined with short-term posaconazole therapy for cutaneous mucormycosis caused by Rhizopus oryzae infection secondary to acute myeloid leukemia: a case report

Cutaneous mucormycosis is a rare fungal infection marked by skin abscesses, swelling, necrosis, dry ulcers, and eschars. Though less fatal compared to other mucormycosis forms, delayed diagnosis and treatment in immunocompromised patients can cause the infection to spread to vital organs, becoming life-threatening. We report a case of lower extremity cutaneous mucormycosis secondary to acute myeloid leukemia, successfully managed with sustained surgical debridement and short-term oral posaconazole. This case highlights the effectiveness of surgical debridement and the potential for short-course antifungal therapy in managing cutaneous mucormycosis.

Left hand abscess as a paradoxical reaction during treatment of disseminated tuberculosis in immunocompetent patient: case report and review of literature

A paradoxical reaction (PR) during the treatment of tuberculosis was defined as the worsening of preexisting disease either clinically or radiologically or the appearance of a new tuberculous lesion. These reactions are frequently observed in patients coinfected with human immunodeficiency virus (HIV) upon the initiation of antiretroviral therapy (ART). Herein, we present a unique case of a paradoxical reaction in a previously healthy 19-year-old female who started anti-tuberculosis treatment for disseminated tuberculosis. Four weeks after treatment initiation, she developed two new swollen masses in her left dorsum of the hand, accompanied by fever and new right submandibular painful lymphadenopathy, with worsening of the preexisting left lower neck lymph node. The patient underwent needle aspiration from her new skin abscess on the dorsum of her left hand, which revealed positive polymerase chain reaction (PCR) for Mycobacterium tuberculosis. Anti-tuberculosis treatment was continued, and the patient fully recovered. We described an unusual presentation of paradoxical reaction manifested by a skin abscess at a site distant from her primary disease in an immunocompetent TB patient, which demonstrated the importance of considering paradoxical reactions in HIV-negative patients who present with worsening signs and symptoms after initial improvement following treatment initiation.

Scarring Cutaneous Tubercular Abscess in a Patient with Lymphoblastic Lymphoma

Scarring Cutaneous Tubercular Abscess in a Patient with Lymphoblastic Lymphoma

Phenotypes of 126 Moroccan HIES patients according to NIH Score.

Hyper-IgE syndrome is a group of inborn errors of immunity, some of which are syndromic, characterized clinically by the classic triad of chronic eczema, cutaneous and/or pulmonary staphylococcal infections and high serum IgE concentrations (> 2000 IU/ml or > 10 x normal for age). We report here the clinical and immunological aspects of Moroccan patients presenting probable or possible HIES according to NIH-HIES score. This retrospective study covers the period from 1998 to 2023 and includes Moroccan patients with a clinical presentation suggestive of HIES (skin and/or pulmonary infections, eczema, high IgE levels) and an NIH score ≥ 20. We attempted to classify the patients phenotypically according to the 2022 IUIS IEI Expert Committee classification. Median age at symptom onset was 0.5 years and median age at diagnosis was 5.5 years. The main clinical signs were eczema (66%), skin abscesses (32.5%), pneumonia (32.5%), otitis (20%), mucocutaneous candidiasis (19%), diarrhea (12%), facial dysmorphism (10.3%), lymphadenopathy (9.5%), bronchial dilation (8%), pneumatoceles (8%), conjunctivitis (7.1%), rhinitis (6.3%), psychomotor delay (5.6%), pathological fractures (4%), retention of deciduous teeth (4%), cognitive delay (3.2%). This is the first clinical description of a cohort of Moroccan patients presenting HIES according to NIH criteria. Phenotype can sometimes orient towards identification of the mutated gene, but the overlapping clinical signs make molecular analysis necessary for genetic counseling and appropriate treatment.

Versatile self-assembled near-infrared SERS nanoprobes for multidrug-resistant bacterial infection-specific surveillance and therapy

The rise of multidrug-resistant bacteria (MDRB) has made bacterial infection one of the biggest health threats, causing numerous antibiotics to fail. Real-time monitoring of bacterial disease treatment efficacy at the infection site is required. Herein, we report a versatile Raman tag 3,3′-diethylthiatricarbocyanine iodide (DTTC)-conjugated star-shaped Au-MoS2@hyaluronic acid (AMD@HA) nanocomposite as a surface-enhanced Raman scattering (SERS) nanoprobe for quick bacterial identification and in-situ eradication. Localized surface plasmon resonance (LSPR) from the hybrid metallic nanostructure makes AMD@HA highly responsive to the near-infrared laser, enabling it to demonstrate a photothermal (PTT) effect, increased SERS activity, and peroxidase-like catalytic reaction to release reactive oxygen species. The tail vein injection of AMD@HA nanoprobes is invasive, however SERS imaging for bacterial identification is non-invasive and sensitive, making it an efficient residual bacteria monitoring method. The detection limit for methicillin-resistant Staphylococcus aureus (MRSA) is as low as 102 CFU·mL-1, and the substrates allow for taking 120 s to acquire a Raman image of 1600 (40 × 40) pixels. In mouse models of MRSA-induced wound infection and skin abscess, the combination of AMD@HA-mediated PTT and catalytic therapy demonstrates a synergistic effect in promoting wound healing through rapid sterilization. This SERS-guided therapeutic approach exhibits little toxicity and does not cause considerable collateral damage, offering a highly promising intervention for treating diseases caused by MDRB. Statement of significanceThis research introduces a SERS nanoprobe, AMD@HA, for the rapid identification and eradication of multidrug-resistant bacteria (MDRB), a critical health threat. The nanoprobe leverages localized surface plasmon resonance for photothermal therapy and enhanced Raman signals, offering a sensitive, non-invasive diagnostic tool. With a low detection limit for MRSA and a synergistic therapeutic effect in mouse models, our approach holds significant promise for treating MDRB-driven infections with minimal toxicity, advancing the field of antimicrobial strategies.

A Case of Hypercalcemia Due to Peritoneal Sarcoidosis Presenting as Appendicitis and Recurrent Sterile Intra-abdominal Abscess with Skin Fistula

A Case of Hypercalcemia Due to Peritoneal Sarcoidosis Presenting as Appendicitis and Recurrent Sterile Intra-abdominal Abscess with Skin Fistula

The identification of Finegoldia dalianensis sp. nov., isolated from the pus of the patient with skin abscess and genomic analysis of the strains belonging to Finegoldia genus

ObjectivesTo comprehensively characterize a new species, named Finegoldia dalianensis sp. nov., isolated from the pus of a skin abscess from a patient and genomic analysis of the strains belonging to Finegoldia genus. MethodsStrain LY240594T was definitively characterized through phylogenetic, genomic, and biochemical approach. Extensive genomic comparisons, involving the genome of LY240594T and those of 82 Finegoldia strains from GenBank, were instrumental in revealing genetic relationships within the Finegoldia genus. ResultsStrain LY240594 was initially identified as F. magna based on MALDI-TOF MS analysis, showing 99.7% 16S rRNA gene sequence similarity with the type strain of F. magna CCUG 17636T. However, there were 68.5% similarity with dDDH method and 90.9% similarity by ANI analysis respectively, between LY240594T and the selected type strain, F. magna DSM 20470T.Biochemical differences were also found between two strains. The ANI and genomic analysis of 82 Finegoldia sp. strains and Strain LY240594 revealed that those strains could be categorized into at least three groups using a 95% ANI threshold. ConclusionComprehensive characterization supported the proposal of a new species within the genus Finegoldia, named Finegoldia dalianensis sp. nov. The type strain, LY240594T (=GDMCC 1.4375T =KCTC 25838T), features 1,938 genes and a G+C content of 31.8 mol%. Genomic comparisons and ANI studies elucidated substantial heterogeneity within the Finegoldia genus.

Development and Evaluation of Herbal Antiacne Gel Formulation Using Curcumin Phytosomes .

Acne vulgaris is a persistent inflammatory condition affecting the pilosebaceous unit that manifests as various skin lesions, including papules, comedones, cysts, pustules, and abscesses. Curcumin, extracted from Curcuma longa rhizomes (Family: Zingiberaceae), is identified for its potent antioxidant, wound-healing, and anti-inflammatory properties. This study aimed to develop an herbal antiacne gel formulation incorporating bioactive curcumin in phytosomes. The formulated gel was evaluated for several physicochemical properties, including pH, spreadability, viscosity, drug content, etc. Additionally, the optimized gel formulation was tested for its in-vitro antiacne action against Propionibacterium acnes. Results showed that developed antiacne gel containing curcumin phytosomes was comparable to a commercially available antiacne product. Stability studies demonstrated that the formulated product remained stable for three months under accelerated stability conditions as per ICH guidelines.

Comparative Study on Healing Frequencies: Packing versus Primary Closure in Surgically Drained Skin Abscesses

Background: Localized collection of pus in skin abscesses caused by bacterial infections always required surgical drainage which is usually accompanied by wound packing or primary closure. Objectives: The objectives of the present study were to evaluate which of these two methods is faster in healing, caused less postoperative pain, patients stayed less in the hospital and created less complications after surgery. Methodology: A comparative study was conducted on 100 patients with acute skin abscesses. Group A was the packing group and group B was the primary closure group, and patients were equally divided. Findings were gathered on the based of time to heal, Visual Analog Scale(VAS) pain score, hospital stay, recurrence rate and complication rate. SPSS version 27.0 was used, descriptive statistics were performed using the T-test and Chi-square test ( p≤0.05) was considered statistically significant Results: The primary closure group showed statistically better results in terms of healing time, length of hospital stay, postoperative pain, and incidence of complications compared to the packing group. Recurrence rates were slightly higher in the packing group, but the difference was not statistically significant. Conclusion: The present study has suggested that primary closure was better method for overall outcome, therefore these results considered as the method of choice for management of skin abscesses that have been drained surgically for coming surgeons.

The role of male hormones in bacterial infections: enhancing Staphylococcus aureus virulence through testosterone-induced Agr activation.

Staphylococcus aureus is a notorious pathogen predominantly involved in skin and soft tissue infections, exhibiting a distinct innate sex bias. This study explores the influence of testosterone on the virulence of S. aureus and elucidates its underlying mechanisms. Utilizing a skin abscess model in intact and castrated male mice, we assessed the effects of testosterone on S. aureus pathogenicity. Compared to controls, castrated mice showed significantly reduced abscess sizes and decreased bacterial loads, highlighting the role of testosterone in modulating the severity of S. aureus infections. In vitro experiments revealed that testosterone enhances the hemolytic activity, cytotoxicity, and oxidative stress resistance of S. aureus. Real-time quantitative PCR analysis showed a significant upregulation of the genes encoding α-hemolysin (hla) and phenol-soluble modulin (psmα). Importantly, testosterone treatment significantly enhanced the expression of the accessory gene regulator (Agr) quorum-sensing system components (agrC, agrA, agrB, agrD), while the SaeRS system (saeR, saeS, and sbi) exhibited only slight changes. Gene knockout experiments revealed that deletion of agrC, rather than saeRS and agrBD, abolishes the testosterone-induced enhancement of hemolysis and gene expression, underscoring the key role of AgrC. Molecular docking simulations indicated a direct interaction between testosterone and AgrC protein, with a strong binding affinity at the active site residue SER201. This study provides new insights into the mechanistic basis of how testosterone enhances the pathogenicity of S. aureus, potentially contributing to increased male susceptibility to S. aureus infections and offering a targeted approach for therapeutic interventions.

Discovery of membrane-targeting amphiphilic honokiol derivatives containing an oxazolethione moiety to combat methicillin-resistant Staphylococcus aureus (MRSA) infections

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major pathogen causing infections in hospitals and the community, and there is an urgent need for the development of novel antibacterials to combat MRSA infections. Herein, a series of amphiphilic honokiol derivatives containing an oxazolethione moiety were prepared and evaluated for their in vitro antibacterial and hemolytic activities. The screened optimal derivative, I3, exhibited potent in vitro antibacterial activity against S. aureus and clinical MRSA isolates with MIC values of 2–4 μg/mL, which was superior to vancomycin in terms of its rapid bactericidal properties and was less susceptible to the development of resistance. The SARs analysis indicated that amphiphilic honokiol derivatives with fluorine substituents had better antibacterial activity than those with chlorine and bromine substituents. In vitro and in vivo toxicity studies revealed that I3 has relatively low toxicity. In a MRSA-infected mouse skin abscess model, I3 (5 mg/kg) effectively killed MRSA at the infected site and attenuated the inflammation effects, comparable to vancomycin. In a MRSA-infected mouse sepsis model, I3 (12 mg/kg) was found to significantly reduce the bacterial load in infected mice and increase survival of infected mice. Mechanistic studies indicated that I3 has membrane targeting properties and can interact with phosphatidylglycerol (PG) and cardiolipin (CL) of MRSA cell membranes, thereby disrupting MRSA cell membranes, further inducing the increase of reactive oxygen species (ROS), protein and DNA leakage to achieve rapid bactericidal effects. Finally, we hope that I3 is a potential candidate molecule for the development of antibiotics to conquer superbacteria-related infections.

SP1.9 - Management of cutaneous abscesses and infected sebaceous cysts using inhaled methoxyflurane Penthrox®: a 12 month prospective observational study

Abstract Aims Incision and drainage of abscesses contribute a significant burden upon emergency general surgical theatres. The purpose of this study was to look at the safety and effectiveness of incision and drainage using inhaled methoxyflurane (Penthrox®) to reduce reliance upon surgical theatres and provide an effective alternative to local anaesthetic. Methods After a successful pilot of 20 patients, adults with ‘simple’ abscesses were enrolled over a 12-month period and given inhaled methoxyflurane for ward-based incision and drainage. Pilonidal and perianal abscesses, patients with ASA ≥3 and abscesses greater than 5cm in size were excluded. Length of admission and outcomes at 1 week, 1 month and 3 months post procedure were compared to previously audited data on simple abscess drainage in theatre to determine safety, efficacy and cost-savings. Results 130 patients had an abscess drained using Penthrox® inhaled analgesia. 93.8% (122/130) had successful drainage with a mean admission time of 99 minutes. Eight patients reattended for further treatment (3<3 months, 3<1 month and 2<1 week); two patients required antibiotics and five required further drainage. Patients taken to theatre spent on average 34.5 hours in hospital compared to 1.65 hours for those performed using Penthrox®. A patient feedback tool captured very positive comments with no negative experiences recorded. Conclusion Penthrox® is a safe, effective analgesic for the incision and drainage of simple abscesses and patient experience is overwhelmingly positive. In addition, it significantly reduces the burden on emergency theatres and the hospital bed-base with an estimated minimum saving of £1704 per patient.

Actinomyces timonensis: A Novel Pathogen to Not Overlook in Immunocompetent Children With Recurrent Cutaneous Abscesses.

Actinomyces timonensis: A Novel Pathogen to Not Overlook in Immunocompetent Children With Recurrent Cutaneous Abscesses.

Vacuum Sealing Drainage against Surgical Site Infection after Intracranial Neurosurgery.

Background: Surgical site infections (SSIs) remain a conundrum for neurosurgeons. This study examines the efficacy and outcome of vacuum sealing drainage (VSD) in the treatment of pyogenic SSIs following intracranial neurosurgery. Methods: Twenty patients with SSIs, who received surgical intervention, were treated retrospectively with VSD during the past five years. Primary surgical procedure types, SSI types, VSD replacements, pathogenic germs, antibiotic therapy, and infection control were reviewed and discussed. Results: Of the 20 infections, 13 (65%) were extradural and 7 (35%) were extradural SSIs combined with intracranial infections (including 5 meningitis, 1 subdural abscess, and 1 brain abscess). All the patients consented to medical device implantation (including 5 titanium webs, 6 bone flap fixation devices, and 12 duraplasties), most of which were removed during debridement. The median duration from primary surgical procedure to an SSI diagnosis was 19 days (range: 7 to 365 d). All the patients also agreed to debridement and VSD treatment; VSD was replaced 0 to 5 times (median, one time) every 4 to 7 days and kept for 4 to 35 days (median, 14 d). Seven (35%) patients had defined bacterial infections, with Staphylococcus aureus being the dominant infection. The deployed standard VSD and antibiotic treatment ensured full recovery from SSIs, including from intracranial infections: 14 (70%) patients had recovered fully by follow-up, and no infection-associated death was registered; 6 (30%) patients died of severe primary affections. Conclusion: VSD-assisted therapy is safe and effective against SSIs after intracranial neurosurgery.

De Novo Deep Intron ELANE Mutation Resulting in Severe Congenital Neutropenia.

Severe congenital neutropenia (SCN) comprises a diverse range of rare hematological disorders characterized by recurrent, often life-threatening infections that manifest within the first months of life. Mutations in the ELANE gene are the most prevalent cause of SCN. While over 230 mutations in ELANE have been documented, including substitutions, frameshifts, nonsense mutations, and splice site alterations, the occurrence of deep intronic mutations has not been previously reported. Herein, we present the case of a young girl who exhibited recurrent fever, respiratory infections, skin abscesses, and gingivitis shortly after birth. Laboratory analysis revealed markedly diminished neutrophil levels alongside elevated monocyte and eosinophil counts. Bone marrow examination disclosed a halt in myelopoiesis maturation. ELANE gene full-length sequencing identified a novel de novo deep intron mutation in ELANE (c.598 + 79G > T), subsequently confirmed by Sanger sequencing. cDNA sequencing of the patient demonstrated aberrant gene splicing. Utilizing a mini-gene splicing assay for ELANE intronic variants, we identified a mutant ELANE allele (c.597 + 1_597 + 83ins) leading to the creation of a premature termination codon (p.Gly200ValfsTer40). Confocal microscopy revealed heightened expression of myeloperoxidase and neutrophil elastase in the patient, suggesting a potential role for the unfolded protein response in the pathogenesis of the deep intron ELANE mutation. In summary, our findings illustrate the first reported instance of de novo deep intron ELANE mutations associated with SCN, underscoring the importance of exploring deep intronic regions in SCN patients lacking identifiable disease-causing gene mutations.

Magnetic Resonance Imaging and 99Tc WBC-SPECT/CT Scanning in Differential Diagnosis between Osteomyelitis and Charcot Neuroarthropathy: A Case Series.

Distinguishing between Charcot Neuroarthropathy (CN), osteomyelitis (OM), and CN complicated with superimposed OM in diabetic patients is crucial for the treatment choice. Given that current diagnostic methods lack specificity, advanced techniques, e.g., magnetic resonance imaging (MRI) and 99mTc-HMPAO-WBC Single Photon Emission Computed Tomography (SPECT/CT), are needed. This study addresses the challenges in distinguishing OM and CN. We included diabetic patients with CN and soft tissue ulceration. MRI and 99mTc-HMPAO-WBC SPECT/CT were used for the diagnosis. The patients were classified into three probability levels for OM (i.e., Definite, Probable, and Unlikely) according to the Consensus Criteria for Diabetic Foot Osteomyelitis (CC-DFO). Eight patients met the eligibility criteria. MRI, supported by SPECT-CT and CC-DFO, showed consistency with the OM diagnosis in three cases. The key diagnostic features included the location of signal abnormalities and secondary features such as skin ulcers, sinus tracts, and abscesses. Notably, cases with inconclusive MRI were clarified by SPECT/CT, emphasizing its efficacy in challenging scenarios. The primary objective of this study was to compare the results of MRI and 99mTc-HMPAO-WBC SPECT/CT with the CC-DFO score in the diabetic foot with CN and suspected OM. Advanced imaging offers a complementary approach to distinguish between CN and OM. This can help delineate the limits of the disease for presurgical planning. While MRI is valuable, 99mTc-HMPAO-WBC SPECT/CT provides additional clarity, especially in challenging cases or when metallic implants affect MRI accuracy.

Mining human microbiomes reveals an untapped source of peptide antibiotics

Drug-resistant bacteria are outpacing traditional antibiotic discovery efforts. Here, we computationally screened 444,054 previously reported putative small protein families from 1,773 human metagenomes for antimicrobial properties, identifying 323 candidates encoded in small open reading frames (smORFs). To test our computational predictions, 78 peptides were synthesized and screened for antimicrobial activity invitro, with 70.5% displaying antimicrobial activity. As these compounds were different compared with previously reported antimicrobial peptides, we termed them smORF-encoded peptides (SEPs). SEPs killed bacteria by targeting their membrane, synergizing with each other, and modulating gut commensals, indicating a potential role in reconfiguring microbiome communities in addition to counteracting pathogens. The lead candidates were anti-infective in both murine skin abscess and deep thigh infection models. Notably, prevotellin-2 from Prevotella copri presented activity comparable to the commonly used antibiotic polymyxin B. Our report supports the existence of hundreds of antimicrobials in the human microbiome amenable to clinical translation.

Phenotypic and genomic analysis of the hypervirulent methicillin-resistant Staphylococcus aureus ST630 clone in China.

Methicillin-resistant Staphylococcus aureus (MRSA) sequence type 630 (ST630) is a rarely reported lineage worldwide. This study aimed to trace the dissemination of the emerging MRSA ST630 clones in China and investigate their virulence potential. We collected 22 ST630-MRSA isolates from across China and performed whole-genome sequencing analysis and virulence characterization on these isolates. Epidemiological results showed that MRSA ST630 isolates were primarily isolated from pus/wound secretions, mainly originating from Jiangxi province, and carried diverse virulence and drug resistance genes. Staphylococcal cassette chromosome mec type V (SCCmec V) predominated (11/22, 50.0%) among the MRSA ST630 isolates. Interestingly, nearly half (45.5%) of the 22 ST630-MRSA isolates tested lacked intact SCCmec elements. Phylogenetic analysis demonstrated that ST630-MRSA could be divided into two distinct clades, with widespread dissemination mainly in Chinese regions. Five representative isolates were selected for phenotypic assays, including hemolysin activity, real-time fluorescence quantitative PCR, western blot analysis, hydrogen peroxide killing assay, blood killing assay, cell adhesion and invasion assay, and mouse skin abscess model. The results showed that, compared to the USA300-LAC strain, ST630 isolates exhibited particularly strong invasiveness and virulence in the aforementioned phenotypic assays. This study described the emergence of a highly virulent ST630-MRSA lineage and improved our insight into the molecular epidemiology of ST630 clones in China.IMPORTANCEMethicillin-resistant Staphylococcus aureus (MRSA) sequence type 630 (ST630) is an emerging clone with an increasing isolation rate in China. This study raises awareness of the hypervirulent MRSA ST630 clones in China and alerts people to their widespread dissemination. ST630-staphylococcal cassette chromosome mec V is a noteworthy clone in China, and we present the first comprehensive genetic and phenotypic analysis of this lineage. Our findings provide valuable insights for the prevention and control of infections caused by this emerging MRSA clone.

Induction of biofilm in extended-spectrum beta-lactamase Staphylococcus aureus with drugs commonly used in pharmacotherapy

Staphylococcus aureus is a bacterial pathogen that causes bloodstream infections, pneumonia, and skin abscesses and is the primary pathogen responsible for medical devices associated with biofilm infections, accounting for approximately 70 % of cases. Therefore, the World Health Organization (WHO) has designated this microorganism as a top priority due to its role in causing over 20,000 bacteremia-related deaths in the US each year. The issue of pathogen resistance to antibiotics, mainly by a biofilm, further complicates these infections since biofilms render the bacterial colony impervious to antibiotics. However, many natural and synthetic substances also induce bacterial biofilm formation. Therefore, we investigated whether the most common active pharmaceutical ingredients (APIs) could induce biofilm formation in two clinical isolates of extended-spectrum beta-lactamase Staphylococcus aureus, one of them also methicillin-resistant (A2M) and two medical devices.We detected biofilm inducers, inhibitors, and destabilizers. Microbial strain, medical devices, API structure, and concentration influenced the modulatory effects of biofilm. In all devices tested, including microplates, FR18 duodenal probe, and respiratory probe, the clinic isolate methicillin-resistant S. aureus A2M exhibited lower susceptibility to biofilm formation than S. aureus A1. The anti-inflammatory acetaminophen, the hypocholesterolemic lovastatin, and the diuretic hydrochlorothiazide all induced biofilm. However, verapamil, an antihypertensive, and cetirizine, an antihistamine, inhibited biofilm on S. aureus A2M, while propranolol, another antihypertensive, inhibited biofilm on S. aureus A1. Additionally, diclofenac, an analgesic, and cetirizine destabilized the biofilm, resulting in more free bacteria and possibly making them more susceptible to external agents such as antibiotics. Nonetheless, further epidemiologic analyses and in vivo assays are needed to confirm these findings and to establish a correlation between drug use, the onset of bacterial infections in patients, and the use of medical devices.This work provides information about the probable clinical implications of drugs in patients using medical devices or undergoing surgical procedures. Inhibitory APIs could also be used as drug repurposing or templates to design new, more potent biofilm inhibitors.