An effective antibiofilm strategy based on bacteriophages armed with silver nanoparticles

The emerging antibiotic resistance in pathogenic bacteria is a key problem in modern medicine that has led to a search for novel therapeutic strategies. A potential approach for managing such bacteria involves the use of their natural killers, namely lytic bacteriophages. Another effective method involves the use of metal nanoparticles with antimicrobial properties. However, the use of lytic phages armed with nanoparticles as an effective antimicrobial strategy, particularly with respect to biofilms, remains unexplored. Here, we show that T7 phages armed with silver nanoparticles exhibit greater efficacy in terms of controlling bacterial biofilm, compared with phages or nanoparticles alone. We initially identified a novel silver nanoparticle-binding peptide, then constructed T7 phages that successfully displayed the peptide on the outer surface of the viral head. These recombinant, AgNP-binding phages could effectively eradicate bacterial biofilm, even when used at low concentrations. Additionally, when used at concentrations that could eradicate bacterial biofilm, T7 phages armed with silver nanoparticles were not toxic to eukaryotic cells. Our results show that the novel combination of lytic phages with phage-bound silver nanoparticles is an effective, synergistic and safe strategy for the treatment of bacterial biofilms.

Bovine Serum Albumin - Hydroxyapatite Nanoflowers as Potential Local Drug Delivery System of Ciprofloxacin

Introduction

Hybrid nanoflowers are structures consisting of organic (enzymes, proteins, nucleic acids) and inorganic components (mostly metal phosphates) with a flower-like hierarchical structure. Novel hybrid nanoflowers based on bovine serum albumin (BSA) and hydroxyapatite (HA) were obtained and characterized. Study on BSA-HA nanoflowers as potential drug delivery system is reported for the first time.

Methods

Embedding ciprofloxacin in the structure of hybrid nanoflowers was confirmed by ATR-FTIR and thermogravimetric analysis. The inorganic phase of the nanoflowers was determined by X-ray diffraction. UV‒Vis spectroscopy was used to evaluate the release profiles of ciprofloxacin from nanoflowers in buffer solutions at pH 7.4 and 5. The agar disk diffusion method was used to study the antibacterial activity of the synthesized nanoflowers against Staphylococcus aureus and Pseudomonas aeruginosa.

Results

Bovine serum albumin - hydroxyapatite nanoflowers were obtained with diameters of ca. 1-2 µm. The kinetics of ciprofloxacin release from nanoflowers were described by the Korsmeyer-Peppas model. The antibacterial activity of the synthesized nanoflowers was demonstrated against S. aureus and P. aeruginosa, two main pathogens found in osteomyelitis.

Conclusion

The formulated nanoflowers may act as an efficient local antibiotic delivery system. Due to the use of nonhazardous, biodegradable components and benign synthesis, hybrid nanoflowers are very promising drug delivery systems that could be applied in the treatment of skeletal system infections.

The potential for bacteriophages and prophage elements in fighting and preventing the gonorrhea

Bacteriophages are the most numerous entities on earth and are found everywhere their bacterial hosts live. As natural bacteria killers, phages are extensively investigated as a potential cure for bacterial infections. Neisseria gonorrhoeae (the gonococcus) is the etiologic agent of a sexually transmitted disease: gonorrhea. The rapid increase of resistance of N. gonorrhoeae to antibiotics urges scientists to look for alternative treatments to combat gonococcal infections. Phage therapy has not been tested as an anti-gonococcal therapy so far. To date, no lytic phage has been discovered against N. gonorrhoeae. Nevertheless, gonococcal genomes contain both dsDNA and ssDNA prophages, and viral particle induction has been documented. In this review, we consider literature data about the attempts of hunting for a bacteriophage specific for gonococci - the gonophage. We also discuss the potential application of prophage elements in the fight against N. gonorrhoeae. Temperate phages may be useful in preventing and treating gonorrhea as a scaffold for anti-gonococcal vaccine development and as a source of lytic enzymes with anti-gonococcal activity.

The effect of sulfur baths on hemorheological properties of blood in patients with osteoarthritis

Balneotherapy is an effective treatment method in various diseases and commonly used treatment modality among patients with musculoskeletal disorders. Sulfur baths are known for healing properties however effect on rheological properties is unstudied. Thus the aim of our study was to determine the effect of sulfur balneotherapy on hemorheological blood indices. A total of 48 patients with osteoarthritis were enrolled to the study. Blood samples were collected twice, before and after 3-week time period. We evaluated complete blood count, fibrinogen, hs-CRP and blood rheology parameters such as elongation index (EI), half-time of total aggregation (T_1/2) and aggregation index (AI) analyzed with the Lorrca Maxis. Mean age of studied cohort was 67 ± 5 years. After sulfur baths WBC count was significantly decreased is studied group (p = 0.021) as well as neutrophile count (p = 0.036). Red blood cell EIs were statistically higher after sulfur baths in shear stress ranging from 8.24 to 60.30 Pa. T_1/2 was significantly higher (p = 0.031) and AI lower (p = 0.003) compared to baseline. No significant changes in fibrinogen and hs-CRP were observed. It is the first study that evaluate effect of sulfur balneotherapy on rheologic properties of blood. Sulfur water baths may improve erythrocyte deformability and aggregation parameters.

Is There a Correlation between Dental Occlusion, Postural Stability and Selected Gait Parameters in Adults?

Background: There is still an ongoing debate about the role of the craniomandibular system, including occlusal conditions, on postural stability. This study aims to assess the role of antero-posterior malocclusion on postural control and plantar pressure distribution during standing and walking. Methods: 90 healthy volunteers (aged 19 to 35) were qualified for the study. The subjects were assigned to three groups, depending on the occlusion type. Each group (Angle Class I, II and III) consisted of 30 people. The research procedure included a clinical occlusal assessment performed by a dentist. Postural control measurements were carried out using a force platform by measuring plantar pressure distribution during standing (six trials with and without visual control) and walking test conditions. Results: The tendency to shift the CoP forward is demonstrated by Angle Class II subjects and backwards by Class I and III subjects (p < 0.001). Individuals with a malocclusion demonstrated significantly higher selected stabilographic parameters while standing on both feet (with eyes open and closed) and during the single-leg test with eyes open (p < 0.05). The analysis of the dynamic test results showed no significant correlations between Angle Classes and the selected gait parameters. Conclusions: Analyses conducted among individuals with malocclusions showed the impact of occlusion on static postural stability. In order to diagnose and effectively treat malocclusion, a multidisciplinary approach with the participation of dentists and physiotherapy specialists is necessary, with the use of stabilometric and kinematic posture assessments.

Revealing the diversity of bacteria and fungi in the active layer of permafrost at Spitsbergen island (Arctic) - Combining classical microbiology and metabarcoding for ecological and bioprospecting exploration

Arctic soils are constantly subjected to extreme environmental conditions such as low humidity, strong winds, high salinity, freeze-thaw cycles, UV exposition, and low nutrient availability, therefore, they have developed unique microbial ecosystems. These environments provide excellent opportunities to study microbial ecology and evolution within pristine (i.e. with limited anthropogenic influence) regions since the High Arctic is still considered one of the wildest and least explored environments on the planet. This environment is also of interest for the screening and recovery of unique microbial strains suitable for various biotechnological applications. In this study, a combination of culture-depended and culture-independent approaches was used to determine the cultivation bias in studies of the diversity of cold-active microorganisms. Cultivation bias is a reduction in recovered diversity, introduced when applying a classical culturing technique. Six different soil types, collected in the vicinity of the Polish Polar Station Hornsund (Spitsbergen, Norway), were tested. It was revealed that the used media allowed recovery of only 6.37 % of bacterial and 20 % of fungal genera when compared with a culture-independent approach. Moreover, it was shown that a combination of R2A and Marine Broth media recovered as much as 93.6 % of all cultivable bacterial genera detected in this study. Based on these results, a novel protocol for genome-guided bioprospecting, combining a culture-dependent approach, metabarcoding, next-generation sequencing, and genomic data reuse was developed. With this methodology, 14 psychrotolerant, multi-metal-resistant strains, including the highly promising Rhodococcus spp., were obtained. These strains, besides increased metal tolerance, have a petroleum hydrocarbon utilization capacity, and thus may be good candidates for future bioremediation technologies, also suited to permanently cold regions.

Pathomechanics, Diagnosis and Treatment of Traumatic Injuries to the Ankle and Subtalar Joints in the Scientific Achievements of the Department of Trauma Surgery and Orthopaedics at the 5th Military Clinical Hospital with Polyclinic, Independent Public Healthcare Centre in Kraków

Introduction: Traumatic injuries to the ankle and subtalar joints constitute severe damage to the locomotor system, both structural and functional. They most often occur in the form of ankle fractures and sprains of the ankle joint, and the least common are peritalar dislocations. Study aim: The aim of the study was to answer the following research questions: 1. What are the most common causes of traumatic injuries to the ankle and subtalar joints, and what are the most common causes of these injures?; 2. What diagnostic methods of traumatic injuries to the ankle and subtalar joints in the analysed period of clinical observation dominated in their imaging?; 3. What are the recommended treatments for traumatic injures of the ankle and subtalar joints? Materials and methods: The aim of the study was carried out on the basis of analysing publications and conference presentations regarding traumatic injuries by employees of the Department of Trauma Surgery and Orthopaedics, the 5th Military Clinic Hospital with Polyclinic, Independent Public Healthcare Centre in Kraków, covering the years from 1992 to 2017. The research methodology, on the other hand, was based on analysis of the content concerning thematically compatible publications and scientific studies with the adopted objectives of the work and established research questions. In the study, 2 thematic monographs (books) were also included, which were published by Państwowy Zakład Wydawnictw Lekarskich (PZWL) [Eng. National Institute of Medical Publishing] in 2020 and 2021 by a retired clinic employee. They are partly based on its clinical material from 1992 to 2017. Results: In the analysed period, 58 of the identified scientific studies were thematically consistent with the adopted research objectives and established research questions. Those were 20 original creative papers (34.5%), 3 review papers (5.2%), 4 case studies (6.9%), 1 postdoctoral dissertation (1.7%), 4 doctoral dissertations (6.9%) and 1 (1.7%) thematic monograph (book), 11 (18.9%) chapters in thematic monographs (book) and 14 (24.2%) conference and convention presentations. Conclusions: 1. The most common causes of traumatic injuries to the ankle and subtalar joints are so-called sports-related injuries or those caused by traffic accidents as well as falls on a hard surface at the same level, especially in people with bone tissue demineralisation disorders. Most often, they are in the form of ankle fractures, and the least common are peritalar dislocations. 2. Clinical diagnosis of traumatic injuries to the ankle and subtalar joints requires manual tests regarding their stability, and imaging examinations are based primarily on ultrasound, MRA and MRI. With regard to post-traumatic instability of the ankle joint, these diagnostics require radiological examination in forced positions. 3. Fractures of the ankle-shin joint require surgical treatment based on the open reposition of bone fragments and their effective stabilisation, as well as on the fixation of tibiofibular syndesmosis. On the other hand, peritalar dislocations can be treated non-operatively, while selected types of damage can be treated surgically. A necessary supplement to the treatment of the traumatic injuries in question is a consistently implemented and individualised programme of physiotherapy.

Antibacterial, Antifungal and Anticancer Activities of Compounds Produced by Newly Isolated Streptomyces Strains from the Szczelina Chochołowska Cave (Tatra Mountains, Poland)

Resistance of bacteria, fungi and cancer cells to antibiotics and other drugs is recognized as one of the major problems in current medicine. Therefore, a search for new biologically active compounds able to either kill pathogenic cells or inhibit their growth is mandatory. Hard-to-reach habitats appear to be unexplored sources of microorganisms producing previously unknown antibiotics and other molecules revealing potentially therapeutic properties. Caves belong to such habitats, and Actinobacteria are a predominant group of microorganisms occurring there. This group of bacteria are known for production of many antibiotics and other bioactive compounds. Interestingly, it was demonstrated previously that infection with bacteriophages might enhance production of antibiotics by them. Here, we describe a series of newly isolated strains of Actinobacteria that were found in caves from the Tatra Mountains (Poland). Phage induction tests indicated that some of them may bear active prophages able to produce virions upon treatment with mitomycin C or UV irradiation. Among all the examined bacteria, two newly isolated Streptomyces sp. strains were further characterized to demonstrate their ability to inhibit the growth of pathogenic bacteria (strains of Staphylococcus aureus, Salmonella enterica, Enterococcus sp., Escherichia coli, and Pseudomonas aeruginosa) and fungi (different species and strains from the genus Candida). Moreover, extracts from these Streptomyces strains reduced viability of the breast-cancer cell line T47D. Chemical analyses of these extracts indicated the presence of isomers of dichloranthrabenzoxocinone and 4,10- or 10,12-dichloro-3-O-methylanthrabenzoxocinone, which are putative antimicrobial compounds. Moreover, various previously unknown (unclassified) molecules were also detected using liquid chromatography-mass spectrometry, suggesting that tested Streptomyces strains may synthesize a battery of bioactive compounds with antibacterial, antifungal, and anticancer activities. These results indicate that further studies on the newly isolated Actinobacteria might be a promising approach to develop novel antibacterial, antifungal, and/or anticancer drugs.

Evaluation of Long-Term Quality of Life Using the Foot and Ankle Outcome Score (FAOS) Questionnaire in Patients Treated by Minimally Invasive Reduction and Percutaneous Stabilization of Intra-Articular Calcaneal Fractures

Background

Treatment of displaced intra-articular calcaneal fractures is controversial. Choosing the optimal surgical technique is very important for patient quality of life and activity. In this study, we asked the question: “What is the long-term quality of life of patients after intra-articular calcaneal fractures treated by minimally invasive reduction and percutaneous stabilization (MIRPS)?”.

Material/Methods

We included 51 patients – 45 males (88%) and 6 females (12%) – who underwent MIRPS of intra-articular calcaneal fractures. The males were ages 22–63 years, with a mean age of 46 years, while the females were aged 31–63, with a mean age of 47 years. The FAOS (Foot and Ankle Outcome Score) survey was used.

Results

Women’s FAOS scores were 72–95%, with a mean of 82%, and varied according to type of fracture, surgery method used, and comorbid fractures. Men’s FAOS scores were 50–95%, with a mean of 84%, and varied according to type of fracture, surgery method used, and comorbid fractures.

Conclusions

According to set criteria regarding the FAOS scale, mainly good and very good results were observed in patients treated surgically for intra-articular calcaneus fractures using MIRPS. Westhues’ method scored a significantly higher foot rating than W-R (Westhues’-Rąpała method). Patients with TTF (tongue-type fracture) scored higher in the FAOS than patients treated with JDTF (joint depression-type fracture). In other cases, no significant differences were observed.

Identification and Characterization of the First Virulent Phages, Including a Novel Jumbo Virus, Infecting Ochrobactrum spp

The Ochrobactrum genus consists of an extensive repertoire of biotechnologically valuable bacterial strains but also opportunistic pathogens. In our previous study, a novel strain, Ochrobactrum sp. POC9, which enhances biogas production in wastewater treatment plants (WWTPs) was identified and thoroughly characterized. Despite an insightful analysis of that bacterium, its susceptibility to bacteriophages present in WWTPs has not been evaluated. Using raw sewage sample from WWTP and applying the enrichment method, two virulent phages, vB_OspM_OC and vB_OspP_OH, which infect the POC9 strain, were isolated. These are the first virulent phages infecting Ochrobactrum spp. identified so far. Both phages were subjected to thorough functional and genomic analyses, which allowed classification of the vB_OspM_OC virus as a novel jumbo phage, with a genome size of over 227 kb. This phage encodes DNA methyltransferase, which mimics the specificity of cell cycle regulated CcrM methylase, a component of the epigenetic regulatory circuits in Alphaproteobacteria. In this study, an analysis of the overall diversity of Ochrobactrum-specific (pro)phages retrieved from databases and extracted in silico from bacterial genomes was also performed. Complex genome mining allowed us to build similarity networks to compare 281 Ochrobactrum-specific viruses. Analyses of the obtained networks revealed a high diversity of Ochrobactrum phages and their dissimilarity to the viruses infecting other bacteria.

Characterization of a Unique Bordetella bronchiseptica vB_BbrP_BB8 Bacteriophage and Its Application as an Antibacterial Agent

Bordetella bronchiseptica, an emerging zoonotic pathogen, infects a broad range of mammalian hosts. B. bronchiseptica-associated atrophic rhinitis incurs substantial losses to the pig breeding industry. The true burden of human disease caused by B. bronchiseptica is unknown, but it has been postulated that some hypervirulent B. bronchiseptica isolates may be responsible for undiagnosed respiratory infections in humans. B. bronchiseptica was shown to acquire antibiotic resistance genes from other bacterial genera, especially Escherichia coli. Here, we present a new B. bronchiseptica lytic bacteriophage—vB_BbrP_BB8—of the Podoviridae family, which offers a safe alternative to antibiotic treatment of B. bronchiseptica infections. We explored the phage at the level of genome, physiology, morphology, and infection kinetics. Its therapeutic potential was investigated in biofilms and in an in vivoGalleria mellonella model, both of which mimic the natural environment of infection. The BB8 is a unique phage with a genome structure resembling that of T7-like phages. Its latent period is 75 ± 5 min and its burst size is 88 ± 10 phages. The BB8 infection causes complete lysis of B. bronchiseptica cultures irrespective of the MOI used. The phage efficiently removes bacterial biofilm and prevents the lethality induced by B. bronchiseptica in G. mellonella honeycomb moth larvae.

Characterization of the virome of Paracoccus spp. (Alphaproteobacteria) by combined in silico and in vivo approaches

Bacteria of the genus Paracoccus inhabit various pristine and anthropologically-shaped environments. Many Paracoccus spp. have biotechnological value and several are opportunistic human pathogens. Despite extensive knowledge of their metabolic potential and genome architecture, little is known about viruses of Paracoccus spp. So far, only three active phages infecting these bacteria have been identified. In this study, 16 Paracoccus strains were screened for the presence of active temperate phages, which resulted in the identification of five novel viruses. Mitomycin C-induced prophages were isolated, visualized and their genomes sequenced and thoroughly analyzed, including functional validation of their toxin-antitoxin systems. This led to the identification of the first active Myoviridae phage in Paracoccus spp. and four novel Siphoviridae phages. In addition, another 53 prophages were distinguished in silico within genomic sequences of Paracoccus spp. available in public databases. Thus, the Paracoccus virome was defined as being composed of 66 (pro)phages. Comparative analyses revealed the diversity and mosaicism of the (pro)phage genomes. Moreover, similarity networking analysis highlighted the uniqueness of Paracoccus (pro)phages among known bacterial viruses.

Insight Into the Diversity and Possible Role of Plasmids in the Adaptation of Psychrotolerant and Metalotolerant Arthrobacter spp. to Extreme Antarctic Environments

Arthrobacter spp. are coryneform Gram-positive aerobic bacteria, belonging to the class Actinobacteria. Representatives of this genus have mainly been isolated from soil, mud, sludge or sewage, and are usually mesophiles. In recent years, the presence of Arthrobacter spp. was also confirmed in various extreme, including permanently cold, environments. In this study, 36 psychrotolerant and metalotolerant Arthrobacter strains isolated from petroleum-contaminated soil from the King George Island (Antarctica), were screened for the presence of plasmids. The identified replicons were thoroughly characterized in order to assess their diversity and role in the adaptation of Arthrobacter spp. to harsh Antarctic conditions. The screening process identified 11 different plasmids, ranging in size from 8.4 to 90.6 kb. A thorough genomic analysis of these replicons detected the presence of numerous genes encoding proteins that potentially perform roles in adaptive processes such as (i) protection against ultraviolet (UV) radiation, (ii) resistance to heavy metals, (iii) transport and metabolism of organic compounds, (iv) sulfur metabolism, and (v) protection against exogenous DNA. Moreover, 10 of the plasmids carry genetic modules enabling conjugal transfer, which may facilitate their spread among bacteria in Antarctic soil. In addition, transposable elements were identified within the analyzed plasmids. Some of these elements carry passenger genes, which suggests that these replicons may be actively changing, and novel genetic modules of adaptive value could be acquired by transposition events. A comparative genomic analysis of plasmids identified in this study and other available Arthrobacter plasmids was performed. This showed only limited similarities between plasmids of Antarctic Arthrobacter strains and replicons of other, mostly mesophilic, isolates. This indicates that the plasmids identified in this study are novel and unique replicons. In addition, a thorough meta-analysis of 247 plasmids of psychrotolerant bacteria was performed, revealing the important role of these replicons in the adaptation of their hosts to extreme environments.

Methods for Bacteriophage Preservation

In a view of growing interest in bacteriophages as the most abundant members of microbial communities and as antibacterial agents, reliable methods for bacteriophage long-term preservation, that warrant the access to original or mutant stocks of unchanged properties, have become of crucial importance. A storage method that retains the infectivity of any kind of bacteriophage virions, either in a cell lysate or in a purified suspension, does not exist, due to the enormous diversity of bacteriophages and hence the differentiation of their sensitivity to various storage conditions. Here, we describe a method of long-term bacteriophage preservation, which is based on freezing of freshly infected susceptible bacteria at early stages of bacteriophage development. The infected bacteria release mature bacteriophages upon melting enabling the recovery of bacteriophage virions with high efficiency. The only limitation of this method is the sensitivity of bacteriophage host to deep-freezing, and thus it can be used for the long-term preservation of the vast majority of bacteriophages.

Bacteriophages as Factories for Eu2O3 Nanoparticle Synthesis

The use of phage display to identify peptides with an ability to bind and synthesize Eu₂O₃ nanoparticles is demonstrated in this report. This is the first report of modified phages specifically binding a lanthanide. The peptides exposed on virions revealed very strong binding to Eu₂O₃ nanoparticles and the ability to catalyze Eu₂O₃ nanoparticles' formation from Eu(OH)₃ and Eu(NO₃)₃ solutions. The luminescence emission spectrum of Eu³⁺ ions indicated that these ions existed mostly in sites deviated from the inversion symmetry in crystalline Eu₂O₃ aggregates and gelatinous Eu(OH)₃ precipitate. The ability of phage-displayed peptides to catalyze formation of Eu₂O₃ nanoparticles provides a useful tool for a low-cost and effective synthesis of lanthanide nanoparticles, which serve as attractive biomedical sensors or fluorescent labels, among their other applications.

Radiological results and clinical complications after calcaneal articular fracture surgical treatment using minimally invasive percutaneous fixation

The choice of method for surgical treatment of articular calcaneal fractures remains problematic due to the potential complications and difficulty in restoring loss of functional status, anatomical geometry and congruence of joint surfaces. The preferred method of surgical treatment for these injuries, among others, is still minimally invasive percutaneous fixation. The aim of this study was to evaluate the radiological results of articular calcaneal fractures surgical treatment using a minimally invasive percutaneous fixation and to determine the prevalence of complications in early and long-term observation. Radiological results of surgical treatment of 82 patients operated using minimally invasive percutaneous fixation were analyzed. The radiological results were based on Bőhler angle and varus angle using criteria according to Harnroongroj and Golec. Postoperative complications were registered in a 3 months follow-up (early observation) and after 6 months (long-term observation). Patients with tongue-type fractures had significantly better surgical outcomes than patients with depression-type fractures. Displacements of bone fragments in articular calcaneal fractures visualized radiographically by the changes of Harnroongroj et al. angle do not constitute a serious surgical problem and are easily repositioned and stabilized, as opposed to displacements resulting in changes in the value of the Böhler angle. The most common postoperative complications were local inflammatory reactions at the point of entry of fixation material and thromboembolic complications. Results of surgical treatment of articular fractures of the calcaneus using a minimally invasive percutaneous fixation are good and satisfactory in majority of patients suggesting that this method constitutes proper choice of treatment.

Surgical complications of intra-articular calcaneal fracture treatment

Introduction: The authors present complications following surgical treatment of intra-articular calcaneus fractures, in regards to the surgical technique employed, based on their own clinical material. Materials and methods: The techniques analyzed included the Westhues’ technique and its modifi cation with additional bone stabilization by Kirschner wires and the percutaneous stabilization by Rapala. The research material covered the years from 1990 to 2012 and consists of 82 operated patients - 68 men (83%) and 14 women (17%). Analyzed calcaneus fractures were divided using the Essex-Lopresti classifi cation. Results: The authors of the article indicate that the most frequently registered complications of surgical treatment of intra-articular calcaneus fractures in early observation were thromboembolic complications and local infl ammatory reactions of the skin at the point of incision and placing the stabilizing material. During the long-term follow-up, the post-thrombotic syndrome and algodystrophic disorders were the most common. Conclusions: Factors contributing to the occurrence of the complications registered were fracture morphology, fixation of bone fragments by an excessive number of stabilizing materials and prolonged immobilization of the operated limb. Cite this article as: Golec P., Tomaszewski K.A., Nowak S., Dudkiewicz Z. Surgical complications of intra-articular calcaneal fracture treatment. Med Rehabil 2016; 20(2): 25-30.

Long-term results and physiotherapeutic determination in operative treatment of intra-articular calcaneal fractures

The authors present their own observations of the surgical treatment of articular calcaneal fractures using a minimally invasive percutaneous fixation in combination with the unifi ed self-developed physiotherapy program. The analyzed techniques include the Westhues’ technique and its modifi cation with additional stabilization of the bone fragments with Kirschner wires, as well as transdermal stabilization by Rąpała. The research material comprises 82 patients with intraarticular fractures - 68 men (83%) and 14 women (17%) treated surgically between 1990 and 2012. The analyzed calcaneus fractures were divided by Essex–Lopresti scale and evaluation of functional outcome at follow-up was based on the Creighton–Nebraska criteria. Men with the “tongue type” fracture treated using the Westhues’ technique had good functional outcomes in 12 cases (17.6%) and acceptable in 7 cases (10.3%). Women with the “tongue type” fracture treated using the Westhues’ technique had good functional outcomes in 2 cases (14.3%) and in one case, poor (7.1%). After analysis of the material, the authors claim that minimally invasive techniques are not really minimally invasive, taking the observed complications into consideration in most of the patients, which lead to the poor functional outcome at long term follow-ups.

"Pros and cons" of total hip arthroplasty with metaphyseal Proxima endoprosthesis

The authors present their own experience concerning total hip arthroplasty with the metaphyseal prosthesis Proxima. Proxima, a metaphyseal prosthesis, provides an innovative supplement to total hip arthroplasty. In this study, the authors present their own experience using Proxima in patients with hip osteoarthritis. This study was performed between 2008 to 2013 and comprised of 62 patients, of which 38 were male (61.3%) and 24 female (38.7%). All patients were operated on due to hip osteoarthritis using total hip arthroplasty with the metaphyseal prosthesis Proxima. The age of patients included into the study ranged from 23 years to 62 years with the mean age of 46 years. The authors paid close attention to the "pros and cons" of surgical techniques and assessed clinical and radiological results in both the short and long-term observation periods. The clinical evaluation was based on the Harris Hip Score and radiological assessment of fixation of the acetabular cup of the endoprosthesis was based on Pradhan's criteria. The endoprosthesis Proxima stem was positioned using the manufacturer's recommended method, evaluating the direction, scope and duration of the displacement in the marrow cavity of the proximal stump of the femur. According to the authors' analysis, the surgery gives good functional and radiological results both in the short- and long-term observation periods. The effectiveness depends on precise qualification for surgery, proper surgical techniques and specific anatomical conditions of the proximal femur stump. The most common reasons for primary and secondary dislocations of the metaphyseal endoprosthesis Proxima stem occur during the first three months post surgery. This is due to incorrect surgical techniques, which disregard the importance of specific anatomical conditions of the proximal femoral stump, which affects Proxima implantation, and cause deviations towards a varus or valgus orientation.

Main health-related quality-of-life issues in patients after a distal radius fracture

AIM

The aim of this study was to identify and assess the degree and clinical course of the main health-related quality-of-life (HRQoL) issues in patients after a distal radius fracture (DRF).

MATERIALS AND METHODS

Patients were eligible if they were between 18-80 years and were within 1-3 days after a non-comminuted DRF. All patients filled out the Polish version of the IOF QLQ, the SF-36 and a demographic questionnaire. Assessment points were set as soon as possible after the fracture, 7 days, 6 weeks, 3 months, and 6 after the fracture. Standard statistical analyses were performed.

RESULTS

During the 16 month recruitment period a total of 71 patients (55 women - 77.5%), with a mean age of 64.1 ± 12.4 years, were included in the study group. All patients suffered from Colles type fractures. Attrition to follow-up was acceptable. At baseline, basing on the IOF QLQ scale scores, DRF patients had the most significant problems with physical function (82.8/100; with 100 representing the worst possible HRQoL), and general health (78.1/100). Basing on SF-36 scale scores patients most significant problems were associated with role limitations due to physical health problems (15.1/100; with 100 representing the best possible HRQoL), and bodily pain (39.5/100).

CONCLUSIONS

Concluding, this study shows that the main issues with which patients with and extra-articular DRF struggle the most are pain of the fractured extremity and physical dysfunction. These symptoms are most pronounced in the early post-injury period, and in the majority of patients steadily decrease over a period of six months.

Proteomic profiles and kinetics of development of bacteriophage T4 and its rI and rIII mutants in slowly growing Escherichia coli

Bacteriophage T4 survival in its natural environment requires adjustment of phage development to the slow bacterial growth rate or the initiation of mechanisms of pseudolysogeny or lysis inhibition (LIN). While phage-encoded RI and probably RIII proteins seem to be crucial players in pseudolysogeny and LIN phenomena, the identity of proteins involved in the regulation of T4 development in slowly growing bacteria has remained unknown. In this work, using a chemostat system, we studied the development of wild-type T4 (T4wt) and its rI (T4rI) and rIII (T4rIII) mutants in slowly growing bacteria, where T4 did not initiate LIN or pseudolysogeny. We determined eclipse periods, phage propagation times, latent periods and burst sizes of T4wt, T4rI and T4rIII. We also compared intracellular proteomes of slowly growing Escherichia coli infected with either T4wt or the mutants. Using two-dimensional PAGE analyses we found 18 differentially expressed proteins from lysates of infected cells. Proteins whose amounts were different in cells harbouring T4wt and the mutants are involved in processes of replication, phage-host interactions or they constitute virion components. Our data indicate that functional RI and RIII proteins - apart from their already known roles in LIN and pseudolysogeny - are also necessary for the regulation of phage T4 development in slowly growing bacteria. This regulation may be more complicated than previously anticipated, with many factors influencing T4 development in its natural habitat.

Novel ZnO-binding peptides obtained by the screening of a phage display peptide library

Zinc oxide (ZnO) is a semiconductor compound with a potential for wide use in various applications, including biomaterials and biosensors, particularly as nanoparticles (the size range of ZnO nanoparticles is from 2 to 100 nm, with an average of about 35 nm). Here, we report isolation of novel ZnO-binding peptides, by screening of a phage display library. Interestingly, amino acid sequences of the ZnO-binding peptides reported in this paper and those described previously are significantly different. This suggests that there is a high variability in sequences of peptides which can bind particular inorganic molecules, indicating that different approaches may lead to discovery of different peptides of generally the same activity (e.g., binding of ZnO) but having various detailed properties, perhaps crucial under specific conditions of different applications.

Inhibition of development of Shiga toxin-converting bacteriophages by either treatment with citrate or amino acid starvation

OBJECTIVES

Shiga toxin-producing Escherichia coli (STEC) are pathogenic strains, whose virulence depends on induction of Shiga toxin-converting prophages and their subsequent lytic development. We explored which factors or conditions could inhibit development of these phages, potentially decreasing virulence of STEC.

MATERIALS AND METHODS

Lytic development of Shiga toxin-converting bacteriophages was monitored after mitomycin C-provoked prophage induction under various conditions. Phage DNA replication efficiency was assessed by measurement of DNA amount in cells using quantitative polymerase chain reaction.

RESULTS

We demonstrated that the use of citrate delayed Shiga toxin-converting phage development after prophage induction. This effect was independent on efficiency of prophage induction and phage DNA replication. However, an excess of glucose reversed the effect of citrate. Amino acid starvation prevented the phage development in bacteria both able and unable to induce the stringent response.

CONCLUSIONS

Lytic development of Shiga toxin-converting bacteriophages can be inhibited by either the presence of citrate or amino acid starvation. We suggest that the inhibition caused by the latter condition may be due to a block in prophage induction or phage DNA replication or both.

APPLICATIONS

Our findings may facilitate development of procedures for treatment of STEC-infected patients.

Persistence of bacteriophage T4 in a starved Escherichia coli culture: evidence for the presence of phage subpopulations

Bacteriophage T4 is able to adjust its development to the growth parameters of the host cell. Here, we present evidence for the production of two different subpopulations of phage particles, which differ in their ability to infect starved Escherichia coli cells. The ability of phage T4 to produce a fraction of virions unable to infect starved cells is linked to the functions of genes rI and rIII, as well as rIIA. This may represent the adaptation of phage T4 in order to persist in unfavourable environmental conditions.

Plasmids derived from Gifsy-1/Gifsy-2, lambdoid prophages contributing to the virulence of Salmonella enterica serovar Typhimurium: implications for the evolution of replication initiation proteins of lambdoid phages and enterobacteria

Gifsy-1 and Gifsy-2 are lambdoid prophages which contribute to the virulence of Salmonella enterica serovar Typhimurium. The nucleotide sequence of the replication region of both prophages is identical, and similar in organization to the replication region of bacteriophage lambda. To investigate the replication of the Gifsy phages and the relationship between Gifsy and host chromosome replication, a plasmid which contained all the genes and regulatory sequences required for autonomous replication in bacterial cells was constructed. This plasmid, pGifsy, was stably maintained in Escherichia coli cells. The helicase loader of the Gifsy phages is very similar to the DnaC protein of the host, a feature characteristic of a large group of prophages common in the sequenced genomes of pathogenic enterobacteria. This DnaC-like protein showed no similarity to the helicase loader of bacteriophage lambda and closely related phages. Interestingly, unlike plasmids derived from bacteriophage lambda (lambda plasmids), pGifsy did not require a gene encoding the putative helicase loader for replication, although deletion of this gene resulted in a decrease in plasmid copy number. Under these conditions, it was shown that the plasmid utilized the helicase loader coded by the host. On the other hand, the viral protein could not substitute for DnaC in bacterial chromosome replication. The results of the current study support the hypothesis that the enterobacterial helicase loader is of viral origin. This hypothesis explains why the gene for DnaC, the protein central to both replication initiation and replication restart in E. coli, is present in the genomes of Escherichia, Shigella, Salmonella and Buchnera, but not in the genomes of related enterobacteria.

Effective inhibition of lytic development of bacteriophages lambda, P1 and T4 by starvation of their host, Escherichia coli

Background

Bacteriophage infections of bacterial cultures cause serious problems in genetic engineering and biotechnology. They are dangerous not only because of direct effects on the currently infected cultures, i.e. their devastation, but also due to a high probability of spreading the phage progeny throughout a whole laboratory or plant, which causes a real danger for further cultivations. Therefore, a simple method for quick inhibition of phage development after detection of bacterial culture infection should be very useful.

Results

Here, we demonstrate that depletion of a carbon source from the culture medium, which provokes starvation of bacterial cells, results in rapid inhibition of lytic development of three Escherichia coli phages, λ, P1 and T4. Since the effect was similar for three different phages, it seems that it may be a general phenomenon. Moreover, similar effects were observed in flask cultures and in chemostats.

Conclusion

Bacteriophage lytic development can be inhibited efficiently by carbon source limitation in bacterial cultures. Thus, if bacteriophage contamination is detected, starvation procedures may be recommended to alleviate deleterious effects of phage infection on the culture. We believe that this strategy, in combination with the use of automated and sensitive bacteriophage biosensors, may be employed in the fermentation laboratory practice to control phage outbreaks in bioprocesses more effectively.