Nidus Of Infection Research Articles

Airway mucus, inflammation and remodeling: emerging links in the pathogenesis of chronic lung diseases.

Airway mucus obstruction is a hallmark of many chronic lung diseases including rare genetic disorders such as cystic fibrosis (CF) and primary ciliary dyskinesia, as well as common lung diseases such as asthma and chronic obstructive pulmonary disease (COPD), which have emerged as a leading cause of morbidity and mortality worldwide. However, the role of excess airway mucus in the in vivo pathogenesis of these diseases remains poorly understood. The generation of mice with airway-specific overexpression of epithelial Na+ channels (ENaC), exhibiting airway surface dehydration (mucus hyperconcentration), impaired mucociliary clearance (MCC) and mucus plugging, led to a model of muco-obstructive lung disease that shares key features of CF and COPD. In this review, we summarize recent progress in the understanding of causes of impaired MCC and in vivo consequences of airway mucus obstruction that can be inferred from studies in βENaC-overexpressing mice. These studies confirm that mucus hyperconcentration on airway surfaces plays a critical role in the pathophysiology of impaired MCC, mucus adhesion and airway plugging that cause airflow obstruction and provide a nidus for bacterial infection. In addition, these studies support the emerging concept that excess airway mucus per se, probably via several mechanisms including hypoxic epithelial necrosis, retention of inhaled irritants or allergens, and potential immunomodulatory effects, is a potent trigger of chronic airway inflammation and associated lung damage, even in the absence of bacterial infection. Finally, these studies suggest that improvement of mucus clearance may be a promising therapeutic strategy for a spectrum of muco-obstructive lung diseases.

A plane screw fixation is a nidus for Paecilomyces sinusitis in a patient with aspirin exacerbated respiratory disease

Titanium plane screw fixation of the frontal sinus is an approach used by otolaryngologists to obliterate this space in an attempt to reduce sinus infections. In this case, however, the titanium used became a nidus of infection which cultured the fungus Paecilomyces. The patient also had a hypersensitivity reaction to mold with positive skin tests and IgE, as well as eosinophilic esophagitis. Treatment entailed anti-fungals, anti-IgE, and fungal immunotherapy to multiple fungal antigens prevalent to the geographic region. The patient also had aspirin exacerbated respiratory disease which responded to aspirin desensitization. Her symptoms resolved after 3 months.

Orbital cellulitis- A review

Orbital cellulitis is an infection of the orbital soft tissues posterior to the orbital septum. It has the potential to be affect sight and function of the eye and extraocular tissues. Although it is commonly seen in the pediatric age group, adult orbital cellulitis is not uncommon. Infection usually originates from sinuses but sometimes the nidus of infection is in the eyelids, from retained vegetative foreign bodies, or very rarely from distant infection spreading to the orbit spread from blood. It is characterized by pain, proptosis, chemosis, diminution of vision, fever, periorbital erythema, and limitation of ocular motility. Historically orbital cellulitis was a sight and life-threatening condition. However, with the advent of high quality imaging, antibiotics and early surgical intervention to drain the orbital abscess when indicated, the chances of visual loss have reduced significantly. The purpose of this review is to describe current investigative and management paradigms in the treatment of orbital cellulitis and current recommendation in the management of complications resulting from it.

The use of locked plate as a definitive fixation for open supracondylar fracture of the femur with partial bone loss in polytraumatized patients

Background Open supracondylar fractures of the femur are complex injuries usually presenting in a polytraumatized patient. Partial circumferential bone loss may result at the time of injury or during debridement. The way in which the fracture is treated has a substantial influence on the local mechanical and biological environment, which in turn will influence the quantity and quality of the osteogenic response. Although early skeletal stabilization can stop the cycle of injury, remove nidus for infection, and halt ongoing hemorrhage, it may be prudent to delay definitive surgery until the patient’s general condition is optimized. Meanwhile, debridement and a preliminary spanning external fixator is used to stabilize the fracture. The use of a locked plate for the fixation of supracondylar fracture of the femur with partial bone loss creates a rigid biomechanical environment needed for healing and maintenance of alignment until fracture healing. Patients and methods Eighteen patients with open supracondylar fracture of the femur were treated between January 2009 and June 2011. All patients were treated surgically within the first 24 h. Radical soft tissue and bone debridement was performed. Thirteen patients underwent definitive fracture fixation using a laterally placed locked distal femur plate. Five patients had their fractures primarily stabilized by an external fixator until improvement of their general condition. Results Bone healing was obvious on follow-up radiographs in 10 patients without the need for supplementary surgical procedures at a mean of 16 (12–20) weeks. Seven patients with no progressive radiologic healing by 20 weeks’ follow-up underwent an iliac crest cancellous bone graft; healing was then realized radiologically after a mean of 12 (8–18) weeks. Using the IOWA knee functional score for final patient assessment, we found excellent results in 14 patients, good results in three patients, and fair results in one patient. Conclusion Generally stable polytraumatized patients should be treated with thorough initial debridement, local antibiotics, and early definitive fracture fixation using a locked distal femur plate. Critically unstable patients with hemorrhagic shock are to be treated with damage control until improvement in their general condition. Bone graft is to be delayed for 20 weeks as many fractures would successfully heal by that time, even with partial bone loss.

The contribution of interleukin-2 to effective wound healing.

Ineffective skin wound healing is a significant source of morbidity and mortality. Roughly 6.5 million Americans experience chronically open wounds and the cost of treating these wounds numbers in the billions of dollars annually. In contrast, robust wound healing can lead to the development of either hypertrophic scarring or keloidosis, both of which can cause discomfort and can be cosmetically undesirable. Appropriate wound healing requires the interplay of a variety of factors, including the skin, the local microenvironment, the immune system, and the external environment. When these interactions are perturbed, wounds can be a nidus for infection, which can cause them to remain open an extended period of time, or can scar excessively. Interleukin-2, a cytokine that directs T-cell expansion and phenotypic development, appears to play an important role in wound healing. The best-studied role for Interleukin-2 is in influencing T-cell development. However, other cell types, including fibroblasts, the skin cells responsible for closing wounds, express the Interleukin-2 receptor, and therefore may respond to Interleukin-2. Studies have shown that treatment with Interleukin-2 can improve the strength of healed skin, which implicates Interleukin-2 in the wound healing process. Furthermore, diseases that involve impaired wound healing, such as diabetes and systemic lupus erythematosus, have been linked to deficiencies in Interleukin-2 or defects Interleukin-2-receptor signaling. The focus of this review is to summarize the current understanding of the role of Interleukin-2 in wound healing, to highlight diseases in which Interleukin-2 and its receptor may contribute to impaired wound healing, and to assess Interleukin-2-modulating approaches as potential therapies to improve wound healing.

Abstract: Assessing the Association Between Seroma and Surgical Site Infection in Immediate Breast Reconstruction

PURPOSE: Several preoperative and intraoperative risk factors have been implicated in infectious complications of immediate breast reconstruction, however the link between common postoperative sequelae and surgical site infection (SSI) remains largely anecdotal. Published rates of seroma and SSI often trend in parallel, and authors have hypothesized that seroma formation may independently promote infectious complications.1,2 The current study aims to assess and quantify the postulated association between seroma and the risk of SSI in immediate breast reconstruction. METHODS: A retrospective review of the Tracking Outcomes and Operations in Plastic Surgery data registry was conducted to identify all cases of immediate breast reconstruction (IBR) between 2009–2012. Cohort characteristics and 30-day outcomes were compared between cases with and without seroma using Pearson’s chi-squared for categorical variables and student t-tests for quantitative variables. Multivariate logistic regression analysis was performed to control for confounding variables while assessing the association between seroma formation and the risk of SSI. RESULTS: Of the 6,729 cases of IBR identified in the study period, 4489 were classified as prosthetic and 2240 as autologous, with 717 pedicled TRAM flaps, 611 latissimus flaps, and 912 free flaps. Acellular dermal matrix (ADM) was used in 17.2% of cases. The seroma rate was 2.9 percent and the SSI rate was 1.9 percent. Bivariate analysis showed that seroma was associated with a 3.6 percent increase in absolute risk of surgical site infection (p<0.0001). Multivariate analysis confirmed that the presence of seroma independently increased the likelihood of SSI in both prosthetic and autologous IBR (odds ratio 7.195,p=0.015; odds ratio, 4.496, p=0.013, respectively). Of note, ADM usage was not associated with SSI when confounding variables were accounted for. CONCLUSION: This study is the first to quantify the independent and statistically significant association between seroma and surgical site infection in immediate breast reconstruction. Seroma is associated with a seven- and four-fold increased likelihood of SSI in prosthetic and autologous reconstruction, respectively. Irrespective of whether postoperative seroma represents an independent nidus of infection or an indicator of aberrant wound healing, our results indicate that a seroma in the setting of recent mastectomy has a greater propensity for infection, and thus we advocate for more attentive surveillance and thoughtful management of seroma following immediate breast reconstruction. REFERENCES: 1. Chun YS, Verma K, Rosen H, et al. Implant-based breast reconstruction using acellular dermal matrix and the risk of post-operative complications. Plast Reconstr Surg 2010;125:429–36. 2. Ganske I, Verma K, Rosen H, et al. Minimizing complications with the use of acellular dermal matrix for immediate implant-based breast reconstruction. Ann Plast Surg. 2013 Nov;71(5):464–70

Interactions of Staphylococcus aureus with ultrasoft hydrogel biomaterials

Ultrasoft biomaterials—polymers, gels, and human soft tissues with an elastic modulus less than ∼100 kPa—are increasingly used in medical devices. While bacterial interactions (adhesion and biofilm formation) have been extensively studied on stiffer materials, little is known about how bacteria colonize ultrasoft materials as a nidus for infection. The goal of this work was to determine how material properties of ultrasoft hydrogels used for dermal fillers might affect pathogenesis of associated infections. We first synthesized a range of polyacrylamide hydrogels (PAAm) with moduli similar to clinically used dermal fillers and characterized the rheological, morphological and porous properties. We then developed a novel microfabricated insert to contain the PAAm in a flow system for quantification of bacterial adhesion and biofilm formation. The rate of adhesion and numbers of adherent Staphylococcus aureus on the surface of PAAm both decreased as the modulus increased. Adhesion was reduced by 3 logs (from 93 × 104/cm2 to 0.083 × 104/cm2) with increasing modulus (from 17 Pa to 654 Pa). However, the number of bacteria in the bulk was the highest within the stiffest gels. This trend was further amplified in subsequent biofilm studies, where interfacial coverage of biofilm decreased as the modulus increased, while the fraction of biofilm in the bulk was the highest within the stiffest gel. The results show significant differences in bacterial colonization of PAAm based on material properties, and reveal how the injection process may unexpectedly create discontinuities that provide a microenvironmental niche for bacterial colonization.

Current Aspects on the Pathogenesis of Urinary Tract Infections

Urinary tract infections are among the most common bacterial infectious diseases worldwide. Every second woman will experience at least one urinary tract infection in her lifetime. The administration of antibiotics has been a safe and efficient treatment modality so far. However, due to the emergence of multi-resistant pathogens and the developmental void of new antimicrobial drugs, the therapy of infections mighty become more challenging in the near future. So, knowledge of the complex host-pathogen interaction is of great importance. Common phenotypes observed in clinical practice suggest basic principles, which are relevant for the development of novel antimicrobial strategies. With invading pathogens forming intracellular bacterial communities they evade host response and provide a nidus for recurrent infection. A plethora of virulence factors allow uropathogenic bacteria to colonize and to establish infections in the urinary tract. In response, host responses seem to address specific virulence mechanisms that are essential to pathogenicity. Deciphering the molecular mechanisms underlying the complex host-pathogen interaction is critical to devise novel treatment options.

Bioresorbable silicon electronic sensors for the brain.

Many procedures in modern clinical medicine rely on the use of electronic implants in treating conditions that range from acute coronary events to traumatic injury. However, standard permanent electronic hardware acts as a nidus for infection: bacteria form biofilms along percutaneous wires, or seed haematogenously, with the potential to migrate within the body and to provoke immune-mediated pathological tissue reactions. The associated surgical retrieval procedures, meanwhile, subject patients to the distress associated with re-operation and expose them to additional complications. Here, we report materials, device architectures, integration strategies, and in vivo demonstrations in rats of implantable, multifunctional silicon sensors for the brain, for which all of the constituent materials naturally resorb via hydrolysis and/or metabolic action, eliminating the need for extraction. Continuous monitoring of intracranial pressure and temperature illustrates functionality essential to the treatment of traumatic brain injury; the measurement performance of our resorbable devices compares favourably with that of non-resorbable clinical standards. In our experiments, insulated percutaneous wires connect to an externally mounted, miniaturized wireless potentiostat for data transmission. In a separate set-up, we connect a sensor to an implanted (but only partially resorbable) data-communication system, proving the principle that there is no need for any percutaneous wiring. The devices can be adapted to sense fluid flow, motion, pH or thermal characteristics, in formats that are compatible with the body's abdomen and extremities, as well as the deep brain, suggesting that the sensors might meet many needs in clinical medicine.

Evaluation of Enterococcus faecalis adhesion, penetration, and method to prevent the penetration of Enterococcus faecalis into root cementum: Confocal laser scanning microscope and scanning electron microscope analysis.

Aim:To ascertain the role of Enterococcus faecalis in persistent infection and a possible method to prevent the penetration of E. faecalis into root cementum.Methodology:One hundred and twenty human single-rooted extracted teeth divided into five groups. Group I (control): intact teeth, Group II: no apical treatment done, Group III divided into two subgroups. In Groups IIIa and IIIb, root apex treated with lactic acid of acidic and neutral pH, respectively. Group IV: apical root cementum exposed to lactic acid and roughened to mimic the apical resorption. Group V: apical treatment done same as Group IV and root-end filling done using mineral trioxide aggregate (MTA). Apical one-third of all samples immersed in E. faecalis broth for 8 weeks followed by bone morphogenetic protein and obturation and again immersed into broth for 8 weeks. Teeth split into two halves and observed under confocal laser scanning microscope and scanning electron microscope, organism identified by culture and polymerase chain reaction techniques.Results:Adhesion and penetration was observed in Group IIIa and Group IV. Only adhesion in Group II and IIIB and no adhesion and penetration in Group I and V.Conclusion:Adhesion and penetration of E. faecalis into root cementum providing a long-term nidus for subsequent infection are the possible reason for persistent infection and root-end filling with MTA prevents the adhesion and penetration.

Esthetic and endodontic management of anterior teeth with impacted foreign objects in the root canals: A case series

Managing trauma to anterior teeth in children is a challenge for dentists. It can be further complicated by the presence of a foreign body in the root canal which acts as an additional nidus of infection. This foreign body is often diagnosed accidentally after radiographic evaluation. Thorough and careful clinical and radiographic assessments are required for complete retrieval of foreign body without much damage to the tooth structure. This paper presents a case series of two case reports where successful complete retrieval of foreign objects was performed from the root canals of permanent incisors followed by esthetic management of the involved teeth.

Ethical obligations when concerned about the work of another dentist

Q I received a call from a dentist who has a highly educated patient who gets “routine cleanings” at his office and gets any necessary treatment from another dentist, Dr. X, who calls himself a “holistic dentist.” Dr. X recommended to the patient that she have 2 mandibular anterior teeth, previously treated endodontically, extracted. The teeth were completely asymptomatic and “within normal limits.” Dr. X told the patient that endodontically treated teeth are a nidus of infection because they contain a foreign body, referring to the endodontic filling material. The patient had the teeth removed and is planning further prosthetic replacement. The questioning dentist was a former member of his state dental board. He recognized Dr. X’s name; Dr. X had been investigated in the past and received a censure for doing the same “treatment” as stated above. What are the ethical obligations of the questioning dentist?

Comparative study of clindamycin concentration in the cerebrospinal fluid after intravenous and intrathecal administration in patients with toxoplasmic meningoencephalitis

Aim of the work: to study the difference of clindamycin concentration in CSF at the intravenous and combined (intrathecal + intravenous) ways of administration of preparation.Materials and methods: study was carried out at the treatment of 11 HIV-positive patients 27-63 years old (men and women) with toxoplasmic meningoencephalitises.There was measured the clindamycin concentration in CSF of every patient after intravenous and combined (intrathecal + intravenous) ways of administration of preparation. The determinations of concentration were done by the way of the reverse-phase high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Statistic processing of the received data was carried out using the Wilcoxon criterion.Results of research. There was received the statistically significant increase of clindamycin concentration in CSF of patients in a day after combined (intrathecal + intravenous) administration of preparation comparing with an intravenous administration.Conclusions. 1. Intrathecal administration of 150 mg. of clindamycin with 8 mg. of dexamethasone is safe.2. Intrathecal administration of 150 mg. of clindamycin with 8 mg. of dexamethasone in combination with an intravenous administration of preparation leads to statistically significant increase of clindamycin concentration in CSF at least during a day after injection.3. Intrathecal administration of clindamycin with dexamethasone in offered doses can be recommended for treatment of meningoencephalitises that caused by microorganisms susceptible to clindamycin.4. If the therapy of toxoplasmic meningoencephalitis was started with an intravenous prescription of clindamycin it is recommended an additional treatment with an intrathecal administration of clindamycin with dexamethasone in offered doses to increase efficiency by creating an effective concentration of preparation in the nidus of infection.5. Intrathecal methods of therapy must be used by the specialists of the respective qualification.

Peculiarities of intensive care at destructive pneumonias in children

In spite of success in treatment and diagnostics attained last years the problem of an acute pneumonia remains actual, this fact is caused by the growing rate of prolonged clinical course and unfavorable clinical outcomes. The growth of antibiotic resistance of microflora is a substantial problem. In addition even the most vigorous modern antibacterial preparations are not effective without an adequate surgical sanitation of the nidus of infection. The aim of the work is to improve the therapy of destructive pneumonia in children that need an intensive care. Methods. 12 patients 9 month – 12 years old who underwent the treatment of heavy community-acquired pneumonia were under observation. There was carried out an X-ray examination at admission and in dynamics, microbiological examination of lavages from the respiratory tract, pleural exudate and blood, determination of laboratory indexes of intoxication (by Kalf-Kalif, Dashtayants, Lubimova) and the level of the middle molecules. The statistical analysis was done using the program package Microsoft Excel and StatSoft 6. Results. In the course of microbiological examination it was demonstrated the prevalence of gram-negative flora and its associations with gram-positive one, the purely gram-positive flora was detected only in 25 % of children. So there was proved an inefficiency of antibiotics that effect mainly on the gram-positive microorganisms. In addition the cephalosporins of the third generation were found insufficiently effective. Such preparations as carbapenems or protected penicillins were chosen in vitro and according to its clinical efficiency. Plasmapheresis and bronchoscopy are useful in the complex therapy. Thoracoscopy must be carried out if the conservative treatment is not effective Conclusions. At present the gram-negative flora and its associations with gram-positive one prevails in etiological structure of the heavy community-acquired pneumonias that must be taken into account choosing the start preparations for empirical therapy. In the cases of insufficient efficiency of conservative therapy an active surgical tactics must be used.

Antimicrobial and surgical management of intra-abdominal infections in children

Complicated intra-abdominal infections are a common problem in children. The etiology of these infections varies by age, with necrotizing enterocolitis being the most common cause in neonates, and appendicitis the most common cause in children. Diagnosis is based on clinical and laboratory findings as well as appropriate imaging studies. These infections are generally the result of mixed gastrointestinal flora, most commonly Escherichia coli and Bacteroides spp. The basic treatment principles for complicated intra-abdominal infections include adequate hemodynamic resuscitation, appropriate antimicrobial therapy, and source control. Antibiotic regimens should include agents effective against common Gram-negative facultative/aerobic bacilli as well as anaerobes. Increased antibiotic resistance has developed among several of the pathogens involved in these infections, which may need to be taken into consideration when selecting empiric therapy. In addition to appropriate antimicrobial therapy, adequate source control has been considered essential in the management of these infections. However, the need for definitive source control procedures in all patients has been challenged, and it has been demonstrated that deferral of these procedures or use of drainage instead of definitive procedures may suffice in selected children and neonates. The advent of laparoscopic procedures has also allowed less invasive approaches to be used in managing the nidus of infection. In this review, some aspects of the etiology, diagnosis and treatment of pediatric intra-abdominal infections will be addressed, particularly with regard to controversies in the use of antimicrobial therapy and source control procedures for these infections.

Intraoperative Contamination of Suction Tips as a Source of Infection during Cesarean Deliveries: A Pilot Study

Objective: To assess risk factors for contamination of suction tips during cesarean deliveries, and correlate these with infectious morbidity. Study design: Yankauer tips were cultured during 100 cesarean deliveries. Positive cultures had growth of greater than or equal to 1,000 colonies/mL. We assessed association of positive cultures with multiple variables using student t-tests and Chi-squared. Results: Cultures were positive in 5% of the specimens, and a 21% contamination rate was noted for growth of at least 100 colonies/mL. Culture positivity was associated with ruptured membranes (p=0.007), rupture greater than 12 hours (p=0.04), cervical dilation greater than 5cm (p=0.04), and use of intrauterine monitors (p=0.03). 15% of patients experienced postoperative infection, but we did not identify an association with culture positivity (p=0.42). During data collection, we noted a change in routine operative procedure, with surgeons discarding the suction tip after it was cultured. Conclusion: While we identified several variables associated with positive cultures, we did not demonstrate an association with infectious morbidity; perhaps reflecting the discarding of suction tip intraoperatively; accordingly, the clinical implications of our findings remain uncertain. Future RCTs comparing continued use versus discarding the suction tip would allow assessment of its role as a nidus for postoperative infection.

Antibodies for HIV prevention in young women.

Young women in sub-Saharan Africa bear a disproportionate HIV burden. They urgently require new HIV prevention approaches that they can use. This review provides an overview of the use of antiretrovirals for HIV preexposure prophylaxis (PrEP), highlighting some of the challenges with this technology and explores the potential role of mAbs for HIV prevention in women. Recent findings on the initial steps in viral entry and establishment of a productive local infectious nidus in the vaginal epithelium has provided important clues for HIV prevention in the female genital tract. Topical and oral formulations of antiretroviral drugs have been shown to prevent HIV infection in women with varying levels of success, depending principally on adherence. Further, several new broad and potent mAbs have been isolated over the last 5 years. Nonhuman primate studies demonstrate that broadly neutralizing HIV mAbs can protect rhesus macaques from simian immunodeficiency virus-HIV chimera (SHIV) infection. These findings have created newfound enthusiasm for passive immunization as a potential prevention strategy for women. If potent broadly neutralizing mAbs are effective in preventing HIV infection in women, this outcome could fill an important gap in HIV prevention technologies for young women, especially in Africa.

Temporizing endovascular repair of a ruptured mycotic abdominal aortic aneurysm.

Ruptured mycotic abdominal aortic aneurysms (MAAAs) present a significant treatment challenge requiring emergency attention to control hemorrhage and hemodynamic compromise, surgical evacuation of the nidus of infection, and restoration of flow to compromised organs. We present a rare case of a MAAA with a contained rupture into the inferior vena cava in the setting of phlegmasia alba dolens of the bilateral lower extremities, sepsis, and significant hemodynamic compromise. A staged, hybrid approach with temporizing endovascular aneurysm repair, followed by extra-anatomic bypass and surgical resection of the MAAA, was performed.

Invasive Aspergillosis Associated with a Foreign Body.

Invasive aspergillosis is a serious complication in immunocompromised individuals. It is associated with a high mortality rate, which demands a combined approach involving radical surgery and antifungal therapy. Here, we describe a patient who presented with nonspecific fever, refractory to antimicrobial agents. Though it primarily involved the nasal cavity and sinuses, it perforated into the oral cavity causing palatal changes. Surprisingly, a foreign body was found in the involved tissues that might have acted as a nidus of infection. A sufficient dose (3 mg/kg/day) of liposomal amphotericin B was initiated soon after a thorough debridement procedure and the patient survived.

An unusual source of septic pulmonary embolism: Perianal abscess in an immunocompetent patient

Septic pulmonary embolism (SPE) is a rare clinical presentation mostly seen in patients who are immunocompromised, in which septic thrombi from an infectious nidus are transported in the vascular system of the lungs. We report a patient presenting with features of sepsis and respiratory distress; chest X-ray and computed tomography (CT) thorax of whom showed multiple bilateral small thick-walled cavities associated with right pleural effusion. He was found to have a septic source of Enterococcus sp. cultured from a perianal abscess with the same bacteremia. Pulmonary septic embolism from the abscess was diagnosed by radiology and correlation of bacteremia from septic foci and blood culture. The clinical condition improved with surgical management of the perianal abscess and appropriate antibiotic treatment.