Community acquired Stenotrophomonas maltophilia discitis: Diagnosis aided by shotgun metagenomic sequencing

Development of a duplex droplet digital PCR assay for the detection of Burkholderia cepacia complex and Stenotrophomonas maltophilia in bloodstream infections

Burkholderia cepacia complex (BCC) and Stenotrophomonas maltophilia are nosocomial pathogens that cause various infections and exhibit high resistance to multiple antimicrobial agents. In this study, we aimed to develop a duplex droplet digital PCR (ddPCR) assay for detecting BCC and S. maltophilia in bloodstream infections. We optimized the experimental conditions by setting the annealing temperature to 51°C and determining the optimal concentrations of primers and probes, as well as the thermal cycle numbers. The feasibility of the duplex ddPCR reaction system with the optimal conditions was established and verified through parallel reactions with reference strains of BCC and S. maltophilia. The specificity of the assay, tested with 33 reference strains, was found to be 100%. The duplex ddPCR assay demonstrated good repeatability and could detect as low as 5.35 copies/reaction of BCC and 7.67 copies/reaction of S. maltophilia. This level of sensitivity was consistent in the simulated blood and blood bottle samples. We compared nucleic acid extraction methods and found that the Chelex-100 boiling method and kit extraction method exhibited similar detection sensitivity, suggesting the potential application of the Chelex-100 boiling method in the ddPCR assay. In the clinical samples, the duplex ddPCR assay accurately detected BCC and S. maltophilia in 58 cases. In conclusion, our study successfully developed a duplex ddPCR assay that provides accurate and convenient detection of BCC and S. maltophilia in bloodstream infections.IMPORTANCEBurkholderia cepacia complex (BCC) and Stenotrophomonas maltophilia are implicated in a wide range of infections, including bloodstream infections (BSIs), pneumonia, and meningitis, and often exhibit high intrinsic resistance to multiple antimicrobial agents, limiting therapeutic options. The gold standard for diagnosing bloodstream infections remains blood culture. However, current blood culture detection and positivity rates do not meet the "rapid diagnosis" required for the diagnosis and treatment of critically ill patients with BSIs. The digital droplet PCR (ddPCR) method is a potentially more powerful tool in the diagnosis of BSIs compared to other molecular methods due to its greater sensitivity, specificity, accuracy, and reproducibility. In this study, a duplex ddPCR assay for the detection of BCC and S. maltophilia in BSIs was developed.

Disseminated Staphylococcus aureus Infection in an Adolescent Patient Following a Traditional Phlebotomy Procedure

Al-Fashdu is a well-known Islamic medicine-based alternative treatment, and it has been widely practiced with the aim of treating certain health issues in various countries. Unfortunately, this therapy can lead to certain complications, including life-threatening infections. We report a case of a 12-year-old male patient who developed a disseminated Staphylococcus aureus infection following Al-Fashdu therapy. He was treated with surgical drainage and intravenous antibiotics. To our knowledge, this is the first report of a disseminated Staphylococcus aureus infection following Al-Fashdu therapy in an adolescent patient.

Clinical metagenomics-challenges and future prospects

Infections lacking precise diagnosis are often caused by a rare or uncharacterized pathogen, a combination of pathogens, or a known pathogen carrying undocumented or newly acquired genes. Despite medical advances in infectious disease diagnostics, many patients still experience mortality or long-term consequences due to undiagnosed or misdiagnosed infections. Thus, there is a need for an exhaustive and universal diagnostic strategy to reduce the fraction of undocumented infections. Compared to conventional diagnostics, metagenomic next-generation sequencing (mNGS) is a promising, culture-independent sequencing technology that is sensitive to detecting rare, novel, and unexpected pathogens with no preconception. Despite the fact that several studies and case reports have identified the effectiveness of mNGS in improving clinical diagnosis, there are obvious shortcomings in terms of sensitivity, specificity, costs, standardization of bioinformatic pipelines, and interpretation of findings that limit the integration of mNGS into clinical practice. Therefore, physicians must understand the potential benefits and drawbacks of mNGS when applying it to clinical practice. In this review, we will examine the current accomplishments, efficacy, and restrictions of mNGS in relation to conventional diagnostic methods. Furthermore, we will suggest potential approaches to enhance mNGS to its maximum capacity as a clinical diagnostic tool for identifying severe infections.

Disseminated Staphylococcus aureus infection after scarification wet cupping therapy: a case report and literature review

BACKGROUND

Cupping therapy is a complementary and alternative medical therapy used especially in pain management. It is generally considered a safe procedure, but complications, including life-threatening infection, may still occur. Understanding these complications is essential to safe and evidence-based use of cupping in practice.

CASE PRESENTATION

Here we report a rare case of disseminated Staphylococcus aureus infection after cupping therapy. After wet cupping, a 33-year-old immunocompetent woman developed fever, myalgia, and a productive cough accompanied by acute liver and kidney injury, iliopsoas abscess, and gastrointestinal bleeding. The patient was treated successfully with cefmetazole plus levofloxacin after microbiological and antimicrobial sensitivity testing.

CONCLUSIONS

Though rarely reported, clinicians, practitioners of cupping therapy, and patients should be aware of the risk of infection after cupping therapy. High hygiene standards are recommended for cupping therapy, even in immunocompetent individuals.

Stenotrophomonas maltophilia and Its Ability to Form Biofilms

In the last ten years, Stenotrophomonas maltophilia has gained increasing interest as an important agent of infection, which is why it has come to be recognized as a serious cause of nosocomial infections related to bloodstream infections, pneumonia, and cancer, mainly in patients with intensive care, and is associated with high mortality rates in immunocompromised patients, with prolonged hospital stays and extensive use of antimicrobials. The importance of this microorganism lies in its low pathogenicity, high multiresistance to various antibiotics, and frequent and persistent isolation in predisposed patients. In addition, few studies have evaluated its epidemiology and clinical relevance. The pathogenesis of biofilms lies mainly in the fact that they can generate persistent chronic infections that are difficult to eradicate. To this extent, it is important to make the characteristics of the biofilm formation behavior of Stenotrophomonas maltophilia known and generate more knowledge about its colonization or infection in humans through this review, which discusses more recent information.

Community-Acquired Stenotrophomonas Maltophilia Infection in a Child: A Case Report and Literature Review

Background

Stenotrophomonas maltophilia (S. maltophilia) is a pathogen causing opportunistic and nosocomial infections that are invasive and fatal, especially in hospitalized and immunocompromised patients. However, community-acquired S. maltophilia is rarely reported in children with normal immunity. S. maltophilia is a multi-drug-resistant bacterium, and the preferred drug is trimethoprim/sulfamethoxazole (TMP/SMX), which has greater side effects in children.

Case Presentation

Herein, we reported the case of a child with clinical manifestations of fever, high C-reactive protein (CRP) and white blood cells, and severe pneumonia. The blood culture yielded S. maltophilia. The initial treatment regimen was meropenem IV, which was subsequently changed to ceftazidime IV, and finally to oral cefixime, which has less side effects in children. The child recovered completely. At the 1-month follow-up, anteroposterior chest X-ray was normal, and the child was in good general health.

Conclusion

Although community-acquired S. maltophilia infection in children is rare, it can occur. The doctor encountered such a child in clinical work. This child has a normal immune system, his disease comes from a community infection and has lobar pneumonia located in the lower lung area. At the same time, the child’s white blood cells and CRP values are high, the doctor should be concerned that the child may have S. maltophilia infection. When treating patients, doctors can try to use drugs empirically, such as ceftazidime, instead of using ciprofloxacin, SMZ and other drugs that have relatively large side effects in children. It is worth mentioning that doctors also need to adjust the medication in a timely manner according to the efficacy evaluation and drug sensitivity of the children after the medication, so as to minimize the drug resistance of community-acquired infections. This will prevent the misuse of Meropenem, which has been given in a community patient and that too in a child. Its important to prevent this malpractise.

Clinical challenges treating Stenotrophomonas maltophilia infections: an update

Stenotrophomonas maltophilia is a non-fermenting, Gram-negative bacillus that has emerged as an opportunistic nosocomial pathogen. Its intrinsic multidrug resistance makes treating infections caused by S. maltophilia a great clinical challenge. Clinical management is further complicated by its molecular heterogeneity that is reflected in the uneven distribution of antibiotic resistance and virulence determinants among different strains, the shortcomings of available antimicrobial susceptibility tests and the lack of standardized breakpoints for the handful of antibiotics with in vitro activity against this microorganism. Herein, we provide an update on the most recent literature concerning these issues, emphasizing the impact they have on clinical management of S. maltophilia infections.

OUP accepted manuscript

Objectives

Cefiderocol is a siderophore cephalosporin active against MDR Gram-negatives including Stenotrophomonas maltophilia. Cefiderocol resistance remains uncommon and incompletely understood. We selected for cefiderocol-resistant S. maltophilia in vitro and characterized the genetic mechanisms and potential for cross-resistance to other antimicrobials.

Methods

We selected cefiderocol resistance in three clinical strains of S. maltophilia by serial passage in escalating concentrations of cefiderocol. Emergent cefiderocol-resistant isolates were subjected to repeat susceptibility testing against a panel of relevant antimicrobials. Isolates with confirmed MIC changes were whole genome sequenced.

Results

Each parent strain was initially susceptible to cefiderocol (MICs of 0.03125, 0.03125 and 0.125 mg/L), and one initially tested susceptible to ceftazidime/avibactam (MIC 4 mg/L). We recovered evolved isolates achieving cefiderocol resistance at MICs of 8–32 mg/L from each parental strain. Some cefiderocol resistant isolates reverted following one to four drug-free passages. Ceftazidime/avibactam MICs of passaged isolates repeatedly increased to ≥256 mg/L, and while other MICs were largely unchanged, trimethoprim/sulfamethoxazole MICs declined 4-fold in two strains. WGS revealed one evolved isolate carrying six coding mutations, while four were isogenic mutants of tonB, tolQ, smf-1 and the smeT promoter. Mutation of the smeT promoter downregulated the smeDEF efflux pump and reduced susceptibility to penicillins but increased susceptibility to several other classes including sulphonamides. Other mutations occurred in genes putatively involved in iron metabolism including smlt1148 and cirA.

Conclusions

S. maltophilia strains evolved cefiderocol resistance through different genetic pathways, but often involved iron transport. Future work is required to fully understand the role(s) of other genes in cefiderocol resistance.

Advances in the Microbiology of Stenotrophomonas maltophilia

Stenotrophomonas maltophilia is an opportunistic pathogen of significant concern to susceptible patient populations. This pathogen can cause nosocomial and community-acquired respiratory and bloodstream infections and various other infections in humans. Sources include water, plant rhizospheres, animals, and foods. Studies of the genetic heterogeneity of S. maltophilia strains have identified several new genogroups and suggested adaptation of this pathogen to its habitats. The mechanisms used by S. maltophilia during pathogenesis continue to be uncovered and explored. S. maltophilia virulence factors include use of motility, biofilm formation, iron acquisition mechanisms, outer membrane components, protein secretion systems, extracellular enzymes, and antimicrobial resistance mechanisms. S. maltophilia is intrinsically drug resistant to an array of different antibiotics and uses a broad arsenal to protect itself against antimicrobials. Surveillance studies have recorded increases in drug resistance for S. maltophilia, prompting new strategies to be developed against this opportunist. The interactions of this environmental bacterium with other microorganisms are being elucidated. S. maltophilia and its products have applications in biotechnology, including agriculture, biocontrol, and bioremediation.

Characteristics, Management and Outcomes of Spondylodiscitis in Children: A Systematic Review

Spondylodiscitis (SD) is the concurrent infection of the intervertebral disc and the adjacent vertebral bodies. Currently, there is a substantial lack of structured reviews about this topic. The aim of this study was to systematically review the available literature in order to determine the main features of pediatric SD. A systematic search of MEDLINE database was performed, according to the PRISMA guideline recommendations. Clinical features, laboratory data, radiological signs, treatments strategies, and outcomes were summarized. Studies’ quality assessments were performed using the JBI Critical Appraisal Checklists. A total of 35 retrospective studies were analyzed and 340 children were identified. The most frequently affected age class was 0.5–4 years. The most affected site was the lumbar spine. The most commonly reported symptoms were back pain (37.97%) and refusal to walk/to stand/to sit (49.79%). The most frequently identified pathogen was Staphylococcus aureus (n = 33). The most used antibiotics were third generation cephalosporins. The intravenous therapy duration range was 1–25 weeks, the oral therapy duration range was 5 days–36 months. Surgery was used in 5.88% of children. In 29 cases clinical sequelae were documented. This study provides the main features of pediatric SD; it also emphasizes the significant gaps in the literature regarding this topic.