Lasse Kvich

Zealand University Hospital · Center for Surgical Sceince

Objective: The aim of this study was to prospectively investigate the incidence of Propionibacterium acnes in thioglycollate broths reported as culture-negative at the Department of Clinical Microbiology, Rigshospitalet, to evaluate whether five days of incubation was enough to find all relevant cases. Method: Five hundred thioglycollate broths...

Induction of a non-culturable state has been demonstrated for many bacteria, e.g., Escherichia coli and various Vibrio spp. In a clinical perspective, the lack of growth due to these non-culturable bacteria can have major consequences for the treatment of patients. Here, we show how anoxic conditioning (restriction of molecular oxygen, O2) generate...

The microtiter assay is one of the most widely used methods for assessing biofilm formation. Though it has high throughput, this assay is known for its substantial deviation from experiment to experiment, and even from well to well. Since the assay constitutes one of the pillars of biofilm research, it was decided to examine the wells of a microtit...

Pseudomonas aeruginosa is generally described as ubiquitous in natural settings, such as soil and water. However, because anecdotal observations and published reports have questioned whether or not this description is true, we undertook a rigorous study using three methods to investigate the occurrence of P. aeruginosa: we investigated environmenta...

Chronic infections present a serious economic burden to health-care systems. The severity and prevalence of chronic infections are continuously increasing due to an aging population and an elevated number of lifestyle related diseases such as diabetes. Treatment of chronic infections has proven difficult, mainly due to the presence of biofilms that...

Background Prosthetic joint infections (PJI) are recalcitrant, hard-to-treat infections and severe complications of joint arthroplasty. Therefore, there is a need to develop new effective treatment strategies, and animal models of high clinical relevance are needed. This study aimed to develop a detailed surgical protocol for hip hemiarthroplasty i...

Background Prosthetic joint infections (PJI) are recalcitrant, hard-to-treat infections and severe complications of joint arthroplasty. Therefore, there is a need to develop new effective treatment strategies, and animal models of high clinical relevance are needed. This study aimed to develop a detailed surgical protocol for inserting a hip hemiar...

Extensive research has explored the role of gut microbiota in colorectal cancer (CRC). Nonetheless, metatranscriptomic studies investigating the in situ functional implications of host-microbe interactions in CRC are scarce. Therefore, we characterized the influence of CRC core pathogens and biofilms on the tumor microenvironment (TME) in 40 CRC, p...

Is it time to rethink the inoculum of animal models of implant-associated infections (IAI)? Traditionally, animal models of IAI are based on inoculation with metabolically active overnight cultures of planktonic bacteria or pre-grown surface-attached biofilms. However, such inoculums do not mimic the clinical initiation of IAI. Therefore, the prese...

Background Bone infections with Staphylococcus aureus are notoriously difficult to treat and have high recurrence rates. Local antibiotic delivery systems hold the potential to achieve high in situ antibiotic concentrations, which are otherwise challenging to achieve via systemic administration. Existing solutions have been shown to confer suboptim...

Objective: Increasing evidence links bacterial dysbiosis with colorectal cancer (CRC) carcinogenesis, with enrichment of core pathogens such as Bacteroides fragilis and Fusobacterium nucleatum. Here, we characterized the in situ biogeography and the molecular interplay between bacteria and the host at the transcriptional level in mucosal colon biop...

Chronic wounds and chronic ulcers are an increasing problem associated with high health care burden and patient burden. The arrested healing of chronic wounds has, in part, been attributed to the presence of biofilms. Substantial research has documented the presence of biofilms in chronic wounds, and many mechanisms of host-pathogen interactions ha...

Background: Evidence suggests that the human gut microbiota modulates the treatment response of immune checkpoint inhibitors (ICI) in cancer. Thus, finding predictive biomarkers in the fecal gut microbiota of patients who are less likely to respond to ICI would be valuable. This systematic review aimed to investigate the association between fecal...

In infections, bacterial cells are often found as relatively small multicellular aggregates characterized by a heterogeneous distribution of phenotype, genotype, and growth rates depending on their surrounding microenvironment. Many laboratory models fail to mimic these characteristics, and experiments are often initiated from planktonic bacteria g...

Due to an increase in underlying predisposing factors, chronic wounds have become an increasing burden on healthcare systems worldwide. Chronic infections often contain biofilm-forming bacteria, which are challenging to eradicate due to increased antibiotic tolerance; thus, new and improved therapeutic strategies are warranted. One such strategy is...

Pseudomonas aeruginosa inhibits or eradicates Staphylococcus aureus in most in vitro settings. Nonetheless, P. aeruginosa and S. aureus are commonly isolated from chronically infected, nonhealing wounds and lungs of people with cystic fibrosis (CF). Therefore, we hypothesized that S. aureus could protect itself from P. aeruginosa through glucose-de...

Several bacterial species are linked to CRC, including Fusobacterium nucleatum and Bacteroides fragilis. However, the biogeography of the bacteria and whether they aggregate in mixed-species biofilms, as seen in some chronic infections, has not been well described. Therefore, we investigated the bacterial biomass (biofilm) and in situ prevalence o...

The use of bone implants and prostheses has contributed to a revolution in modern medicine; however, in the beginning, not much was asked from the implant and prosthetic materials per se. Therefore, the next game-changer in orthopedic research will come from new material designs which for instance can aid in prevention of implant-associated bone in...

Current evidence suggests that bacteria contribute to the development of certain cancers, such as colorectal cancer (CRC), partly by stimulating chronic inflammation. However, little is known about the bacterial impact on molecular pathways in CRC. Recent studies have demonstrated how specific bacteria can influence the major CRC-related pathways,...

This poster was presented at the Danish Surgical Society Annual Meeting (DKS) and displayed the methodological approach to visual characterization of bacteria in colorectal cancer (CRC) carcinogenesis, with particular attention to F. nucleatum and B. fragilis. For this purpose, we developed species-specific, synthetic DNA probes targeting these bac...

The carcinogenic effects of microorganisms have been discovered in multiple cancer types. In urology, the development of squamous cell carcinoma of the bladder due to the parasitic infection with Schistosoma Mansoni is widely accepted. The oncogenic potential of biofilms has been studied in colorectal cancer and experimental studies have shown that...

Coating surfaces with a copper-silver alloy in clinical settings can be an alternative or complementary antibacterial strategy to other existing technologies and disinfection interventions. A newly developed copper-silver alloy coating has a high antibacterial efficacy against common pathogenic bacteria in laboratory setups, and the purpose of this...

Induction of a non-culturable state has been demonstrated for many bacteria. In a clinical perspective, the lack of growth due to these non-culturable bacteria can have major consequences for the diagnosis and treatment of patients. Here we show how anoxic conditioning (restriction of molecular oxygen, O 2 ) generates difficult-to-culture (DTC) bac...

The protozoan parasite Toxoplasma gondii causes severe opportunistic infections. Here, we report an unexpected diagnosis of cerebral toxoplasmosis. T. gondii was diagnosed by 16S and D2LSU rDNA sequencing of a cerebral biopsy specimen and confirmed by T. gondii-specific PCR and immunohistochemistry. The patient was later diagnosed with HIV/AIDS. Co...

Identification of microorganisms usually takes 1-2 days. Using PCR and 16S rDNA sequencing, identification can be obtained the same day and patients can get a specific treatment faster. 16S is a small part of the ribosomal genome in bacteria, which is a conserved part with minimal changes through evolution, allowing differentiation between species...