Kordo Saeed

Engineered honey: In vitro antimicrobial activity of a novel topical wound care treatment

Surgihoney is a novel engineered organic honey product for wound care. Its antimicrobial activity can be controlled and adjusted by the engineering process, allowing preparation of three different potencies, labelled Surgihoney 1-3. Susceptibility testing of a range of wound and ulcer bacterial isolates to Surgihoney by the disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determination, and time-kill measurements by time suspension tests were performed. Surgihoney demonstrated highly potent inhibitory and cidal activity against a wide range of Gram-positive and Gram-negative bacteria and fungi. MICs/MBCs were significantly lower than concentrations likely to be achieved in topical clinical use. The topical concentration of Surgihoney in wounds was estimated at ca. 500g/L. MICs/MBCs for Staphylococcus aureus were 32/125g/L for Surgihoney 1 and 0.12/0.25g/L for Surgihoney 3. Cidal speed depended on potency, being 48h for Surgihoney 1 and 30min for Surgihoney 3. Maintenance of the Surgihoney inoculum preparation for up to a week demonstrated complete cidal activity and no bacterial persistence. Surgihoney has wide potential as a highly active topical treatment combining the effects of the healing properties of honey with the potent antimicrobial activity of the engineered product for skin lesions, wounds, ulcers and cavities. It is highly active against multidrug-resistant bacteria. It is more active than other honeys tested and is comparable with chemical antiseptics in antimicrobial activity.

Measuring synovial fluid procalcitonin levels in distinguishing cases of septic arthritis, including prosthetic joints, from other causes of arthritis and aseptic loosening

ObjectivesDifferentiating septic arthritis from non-septic arthritis can be challenging as the clinical pictures are similar and an efficacious diagnostic test is not yet available. Our objectives in this study were to establish if procalcitonin (PCT) could be reproducibly measured from synovial fluid, if there is a difference in synovial procalcitonin values between patients with septic and non-septic arthritis, respectively, including those with implants and to determine cut-off levels that could be used as a practical tool in the management of these conditions.MethodsUsing a standard serum assay, synovial fluid PCT levels were measured retrospectively in 26 septic and 50 non-septic predefined arthritis cases. The reproducibility of synovial PCT was also assessed at various concentrations.ResultsSynovial PCT can be measured and is reproducible. In this cohort, statistically significant higher synovial PCT levels were found in cases of septic arthritis than in non-septic arthritis. Sensitivities, specificities and positive and negative predictive values varied at different cut-off levels.ConclusionThe test could be added to other microbiological and biochemical tests and may be used to supplement other clinical, radiological and laboratory findings in the assessment of patients with acute painful joints. In our cohort, findings of very high synovial PCT levels supported an infection process, including in prosthesis-related infections. The high negative predictive value of low synovial PCT levels could exclude infection in both native and prosthetic joints. Larger prospective studies are needed to further validate these results and to examine the cost effectiveness of synovial PCT.

Hot topics in the diagnosis and management of skin and soft-tissue infections.

Eighteen hot topics regarding the diagnosis and management of skin and soft-tissue infections (SSTIs) were selected and reviewed by members of the SSTI Working Group of the International Society of Chemotherapy (ISC). Despite the large amount of literature available on the issue selected, there are still many unknowns with regard to many of them and further studies are required to answer these challenging issues that face clinicians on a daily basis.

The value of procalcitonin measurement in localized skin and skin structure infection, diabetic foot infections, septic arthritis and osteomyelitis

Serum procalcitonin (PCT) is an established diagnostic marker for severe or systemic bacterial infections such as pneumonia, sepsis and septic shock. Data regarding the role of PCT in localized infections without systemic inflammatory response syndrome are scarce. The aim of this review is to assess the value of PCT measurements in localized infections such as skin and skin structure infections, diabetic foot infections, septic arthritis (SA) and osteomyelitis. It appears that serum PCT is unlikely to change the clinical practice in skin and skin structure infection. However, serum PCT could have a role in diagnosis and monitoring of diabetic foot infections in hospitalized settings. There are conflicting reports regarding the ability of serum PCT to distinguish SA from non-SA; synovial PCT may be more appropriate in these settings, including in implant-related infections. Better designed studies are needed to evaluate the usefulness of PCT with or without other biomarkers in localized infections.

Cryptic resistance in Staphylococcus aureus: a risk for the treatment of skin infection?

Purpose of review The purpose of this review is to explore major challenges that face routine diagnostic laboratories in detecting cryptic (hidden) antibiotic resistances in Staphylococcus aureus and the impact of these covert resistances in the management of skin and soft tissue infections. Recent findings The review covers recent literature and works regarding a number of evolving mechanisms and forms of antibiotic resistances in S. aureus, including novel oxacillin-susceptible–mecA-positive meticillin-resistant S. aureus (OS-MRSA) strains and MRSA isolates that harbour a divergent mecA homologue termed mecC within the novel staphylococcal cassette chromosome mec XI element. Summary S. aureus strains causing skin and soft tissue infections are evolving with regard to virulence as well as antimicrobial resistance. Cryptic resistances continue to escape routine diagnostic tests. This means that there are still many unknowns regarding their global dissemination, virulence, threats in clinical practice and optimal treatment strategies. Larger studies are needed to further understand the pathogenic consequences of cryptic resistances in S. aureus in skin and soft tissue infections, which may ultimately provide novel preventive or treatment approaches for this significant human pathogen.

Specific staphylococcal polymerase chain reaction can be a complementary tool for identifying causative organisms and guiding antibiotic management in orthopaedic infections

BackgroundVast numbers of bone and joint infections in adults, including prosthetic joint infections, are caused by staphylococci. Because of the complexity of these infections, treatment with broad-spectrum antibiotics active against staphylococci usually is started before sampling. This may be one of the reasons why conventional microbiology cultures fail to identify a causative organism. We sought to demonstrate that a specific duplex Staphylococcus species real-time polymerase chain reaction can aid in the diagnosis and antimicrobial management of these cases. MethodsDeep specimens from 19 patients with presumed bone, joint, or prosthetic joint infection, who had been on anti-staphylococcal antibiotics before surgery, were examined with a specific duplex staphylococcal polymerase chain reaction. Samples including bone, tissue, joint aspirates and fluid were negative on culture using conventional microbiology techniques. ResultsThe polymerase chain reaction resulted in bacteriological identification in 58.7% of the samples and antibiotic treatment was modified accordingly. ConclusionsSpecific staphylococcal polymerase chain reaction can be a useful diagnostic tool in orthopaedic infections especially when conventional cultures fail to grow, this would allow targeted antibiotic therapy.

The impact of PCR in the management of prosthetic joint infections

An accurate diagnosis of prosthetic joint infection (PJI) remains a challenging clinical problem and is essential for the success of treatment regardless of the treatment option chosen by patients and surgeons. In recent years, PCR for the diagnosis of PJI has received much attention. Here, we review the impact of common PCR-based techniques on identifying causative organisms, antibiotic management and economics of PJI.

Novel negative pressure wound therapy with instillation and the management of diabetic foot infections.

Purpose of review The use of negative pressure wound therapy with instillation (NPWTi) in complex or difficult-to-treat acute and chronic wounds has expanded rapidly since the introduction of commercially available NPWTi systems. We summarize the evidence related to NPWTi and particularly focus on the application of this technology in diabetic foot ulcers, diabetic foot infections and postoperative diabetic wounds. Recent findings The benefits of negative pressure wound therapy (NPWT) are well documented in the treatment of complex acute and chronic wounds, including noninfected postoperative diabetic wounds and diabetic foot ulcers. Combining intermittent wound irrigation with NPWT may offer additional benefits compared to NPWT alone, including further reduction of wound bed bioburden, increased granulation tissue formation and provision of wound irrigation in a sealed environment, thus preventing potential cross-contamination events. Recently, available evidence suggests that adjunctive NPWTi may be superior to standard NPWT in the management of diabetic infections following surgical debridement and may promote granulation tissue formation in slow-to-heal wounds. Summary Available evidence relating to the utilization of NPWTi in diabetic foot infections is promising but limited in quality, being derived mostly from case series or small retrospective or prospective studies. In order to confirm or refute the potential benefits of NPWTi in this patient cohort, well designed randomized controlled studies are required that compare NPWTi to NPWT or standard wound care methodologies.

Diagnostics in prosthetic joint infections

Prosthetic joint infection (PJI) poses a significant burden on patients, clinicians and the healthcare economy. Although various tests have been established for the diagnosis of PJI, the diagnosis remains challenging. In this review, established and potential future diagnostic tests are presented, some of which could provide stepping stones towards improved diagnosis, identification of aetiological agents and efficacious therapeutic options for the management of PJI.

Prosthetic joints: shining lights on challenging blind spots

Fifteen hot topics on joint replacement (JR) and prosthetic joint infection (PJI) with controversies and contentious areas were selected and reviewed by members of the Bone and Joint Working Group of the International Society of Chemotherapy (ISC) with co-opted orthopaedic and infection specialist colleagues. A manuscript was prepared, following an in-depth review of the current literature, with the aim of providing an insight into these complex issues and, when applicable, provide personal views from authors’ own experience. There remain many unanswered questions in regards to these and other areas of arthroplasty and more studies are required in some of these fields.