Biofilm Formation is Durably Prevented on Pre-Fabricated Antibiotic Cement Spacers Compared to Cobalt Chrome and Polyethylene.

BACKGROUND: A two-stage revision remains the standard for managing chronic periprosthetic joint infection (PJI). Despite multiple spacer options, whether a particular one better resists biofilm formation remains unclear. Prefabricated polymethylmethacrylate (PMMA) articulating spacers containing antibiotics and a proprietary pore structure were developed to increase antibiotic elution characterized by a rapid burst phase for the initial 1 to 2 days and an extended slow-release phase for > 28 days. This in vitro study determined whether biofilm formation is prevented during the initial rapid burst phase and/or the slow-release phase. METHODS: S. aureus-Xen36 was incubated in 1.5 ml of Luria-Bertani broth with PMMA discs with the proprietary pore structure either with or without gentamycin and vancomycin, or with 'Hoffman style' positive-control discs (ultra-high molecular weight polyethylene (UHMWPE) or cobalt-chrome). Non-adherent bacteria were removed by three Phosphate Buffered Saline rinses every 20 to 24 hours. Planktonic bacterial growth in the culture broth and biofilm formation on the discs were measured by Colony Forming Unit (CFU) counting and resazurin reduction assays. Experiments were repeated > 4 times. RESULTS: No detectable planktonic bacterial growth or biofilm formation occurred in cultures containing PMMA with antibiotics (≤ 15 CFUs/disc), whereas biofilms formed on PMMA without antibiotics, UHMWPE, and cobalt-chrome (1x107 to 4x108 CFUs/disc, P < 0.0001). Biofilm formation was confirmed by a 100-fold decrease in sensitivity to vancomycin. To determine whether the antibiotic slow-release phase is sufficient to block biofilm formation, PMMA discs with antibiotics were pre-eluted for 14 days with multiple saline changes prior to bacterial inoculation. After antibiotic elution, still no detectable biofilms formed on PMMA discs with antibiotics (≤ 15 CFUs/disc, P <0.0001). CONCLUSION: Antibiotic release during both the initial and slow-release phases prevented biofilm formation on PMMA with the proprietary pore structure. This may translate into improved infection eradication rates clinically.

Invasive Fungal Infection After Lung Transplantation: Epidemiology in the Setting of Antifungal Prophylaxis.

BACKGROUND: Lung transplant recipients commonly develop invasive fungal infections (IFIs), but the most effective strategies to prevent IFIs following lung transplantation are not known. METHODS: We prospectively collected clinical data on all patients who underwent lung transplantation at a tertiary care academic hospital from January 2007-October 2014. Standard antifungal prophylaxis consisted of aerosolized amphotericin B lipid complex during the transplant hospitalization. For the first 180 days after transplant, we analyzed prevalence rates and timing of IFIs, risk factors for IFIs, and data from IFIs that broke through prophylaxis. RESULTS: In total, 156 of 815 lung transplant recipients developed IFIs (prevalence rate, 19.1 IFIs per 100 surgeries, 95% confidence interval [CI] 16.4-21.8%). The prevalence rate of invasive candidiasis (IC) was 11.4% (95% CI 9.2-13.6%), and the rate of non-Candida IFIs was 8.8% (95% CI 6.9-10.8%). First episodes of IC occurred a median of 31 days (interquartile range [IQR] 16-56 days) after transplant, while non-Candida IFIs occurred later, at a median of 86 days (IQR 40-121 days) after transplant. Of 169 IFI episodes, 121 (72%) occurred in the absence of recent antifungal prophylaxis; however, IC and non-Candida breakthrough IFIs were observed, most often representing failures of micafungin (n = 16) and aerosolized amphotericin B (n = 24) prophylaxis, respectively. CONCLUSIONS: Lung transplant recipients at our hospital had high rates of IFIs, despite receiving prophylaxis with aerosolized amphotericin B lipid complex during the transplant hospitalization. These data suggest benefit in providing systemic antifungal prophylaxis targeting Candida for up to 90 days after transplant and extending mold-active prophylaxis for up to 180 days after surgery.

Enteral Feeding with Human Milk Decreases Time to Discharge in Infants following Gastroschisis Repair.

OBJECTIVE: To assess the effect of enteral feeding with human milk on the time from initiation of feeds to discharge after gastroschisis repair through review of a multi-institutional database. STUDY DESIGN: Infants who underwent gastroschisis repair between 1997 and 2012 with data recorded in the Pediatrix Medical Group Clinical Data Warehouse were categorized into 4 groups based on the percentage of days fed human milk out of the number of days fed enterally. Cox proportional hazards regression modeling was performed to determine the adjusted effect of human milk on the time from initiation of feeds to discharge. RESULTS: Among 3082 infants, 659 (21%) were fed human milk on 0% of enteral feeding days, 766 (25%) were fed human milk on 1%-50% of enteral feeding days, 725 (24%) were fed human milk on 51%-99% of enteral feeding days, and 932 (30%) were fed human milk on 100% of enteral feeding days. Following adjustment, being fed human milk on 0% of enteral feeding days was associated with a significantly increased time to discharge compared with being fed human milk on 100% of enteral feeding days (hazard ratio [HR] for discharge per day, 0.46; 95% CI, 0.40-0.52). The same was found for infants fed human milk on 1%-50% of enteral feeding days (HR, 0.37; 95% CI, 0.32-0.41) and for infants fed human milk on 51%-99% of enteral feeding days (HR, 0.51; 95% CI, 0.46-0.57). CONCLUSION: The use of human milk for enteral feeding of infants following repair of gastroschisis significantly reduces the time to discharge from initiation of feeds.

Candida infective endocarditis: an observational cohort study with a focus on therapy.

Candida infective endocarditis is a rare disease with a high mortality rate. Our understanding of this infection is derived from case series, case reports, and small prospective cohorts. The purpose of this study was to evaluate the clinical features and use of different antifungal treatment regimens for Candida infective endocarditis. This prospective cohort study was based on 70 cases of Candida infective endocarditis from the International Collaboration on Endocarditis (ICE)-Prospective Cohort Study and ICE-Plus databases collected between 2000 and 2010. The majority of infections were acquired nosocomially (67%). Congestive heart failure (24%), prosthetic heart valve (46%), and previous infective endocarditis (26%) were common comorbidities. Overall mortality was high, with 36% mortality in the hospital and 59% at 1 year. On univariate analysis, older age, heart failure at baseline, persistent candidemia, nosocomial acquisition, heart failure as a complication, and intracardiac abscess were associated with higher mortality. Mortality was not affected by use of surgical therapy or choice of antifungal agent. A subgroup analysis was performed on 33 patients for whom specific antifungal therapy information was available. In this subgroup, 11 patients received amphotericin B-based therapy and 14 received echinocandin-based therapy. Despite a higher percentage of older patients and nosocomial infection in the echinocandin group, mortality rates were similar between the two groups. In conclusion, Candida infective endocarditis is associated with a high mortality rate that was not impacted by choice of antifungal therapy or by adjunctive surgical intervention. Additionally, echinocandin therapy was as effective as amphotericin B-based therapy in the small subgroup analysis.

Rifampin use and safety in hospitalized infants.

OBJECTIVE: This study aims to examine the use and safety of rifampin in the hospitalized infants. STUDY DESIGN: Observational study of clinical and laboratory adverse events among infants exposed to rifampin from 348 neonatal intensive care units managed by the Pediatrix Medical Group between 1997 and 2012. RESULT: Overall, 2,500 infants received 4,279 courses of rifampin; mean gestational age was 27 weeks (5th, 95th percentile; 23, 36) and mean birth weight was 1,125 g (515; 2,830). Thrombocytopenia (121/1,000 infant days) and conjugated hyperbilirubinemia (25/1,000 infant days) were the most common laboratory adverse events. The most common clinical adverse events were medical necrotizing enterocolitis (64/2,500 infants, 3%) and seizure (60/2,500 infants, 2%). CONCLUSION: The overall incidence of adverse events among infants receiving rifampin appears low; however, additional studies to further evaluate safety and dosing of rifampin in this population are needed.

Necrotizing fasciitis caused by Haemophilus influenzae serotype f.

Haemophilus influenzae is a rare cause of soft tissue infection. In this report, we present a case of multifocal necrotizing fasciitis in a healthy adult patient, secondary to Haemophilus influenzae serotype f infection, and we review literature on this rare cause of necrotizing fasciitis.

Cardiovascular Implantable Electronic Device Infections: A Contemporary Review.

Infections associated with cardiac implantable electronic devices (CIEDs) are increasing and are a cause of significant morbidity and mortality. This article summarizes the latest updates with respect to the epidemiology, microbiology, and risk factors for CIED-related infections. It also covers important considerations regarding the diagnosis, management, and prevention of these infections. Newer technologies such as leadless pacemakers and subcutaneous implantable cardioverters and defibrillators are discussed.

Halicin remains active against Staphylococcus aureus in biofilms grown on orthopaedically relevant substrates.

Aims: Biofilm infections are among the most challenging complications in orthopaedics, as bacteria within the biofilms are protected from the host immune system and many antibiotics. Halicin exhibits broad-spectrum activity against many planktonic bacteria, and previous studies have demonstrated that halicin is also effective against Staphylococcus aureus biofilms grown on polystyrene or polypropylene substrates. However, the effectiveness of many antibiotics can be substantially altered depending on which orthopaedically relevant substrates the biofilms grow. This study, therefore, evaluated the activity of halicin against less mature and more mature S. aureus biofilms grown on titanium alloy, cobalt-chrome, ultra-high molecular weight polyethylene (UHMWPE), devitalized muscle, or devitalized bone. Methods: S. aureus-Xen36 biofilms were grown on the various substrates for 24 hours or seven days. Biofilms were incubated with various concentrations of halicin or vancomycin and then allowed to recover without antibiotics. Minimal biofilm eradication concentrations (MBECs) were defined by CFU counting and resazurin reduction assays, and were compared with the planktonic minimal inhibitory concentrations (MICs). Results: Halicin continued to exert significantly (p < 0.01) more antibacterial activity against biofilms grown on all tested orthopaedically relevant substrates than vancomycin, an antibiotic known to be affected by biofilm maturity. For example, halicin MBECs against both less mature and more mature biofilms were ten-fold to 40-fold higher than its MIC. In contrast, vancomycin MBECs against the less mature biofilms were 50-fold to 200-fold higher than its MIC, and 100-fold to 400-fold higher against the more mature biofilms. Conclusion: Halicin is a promising antibiotic that should be tested in animal models of orthopaedic infection.

Mycoplasma hominis hematoma infection in patient following kidney transplant.

Mycoplasma species, specifically Mycoplasma hominis (M. hominis), are commonly associated with genitourinary (GU) tract infectious syndromes. However, Mycoplasma spp. can also be involved in extragenital infections, primarily in immunosuppressed patients. A 61 year old female was successfully treated with moxifloxacin and doxycycline combination therapy for an infected hematoma secondary to M. hominis following a renal transplant. Microbiology technologists noted the growth of pinpoint, translucent non-hemolytic colonies, but no organisms seen on Gram stain. These findings prompted the updated culture report of, "Growth on culture plates, gram stain suggestive of organism lacking cell wall." Empiric antimicrobials were initiated to cover both Mycoplasma spp. and Ureaplasma spp before resulting M. hominis. Initiating empiric therapy directed against Mycoplasma spp. following Gram stain results and before organism speciation may prevent a lapse in effective therapy. This is especially important as perioperative antimicrobial prophylaxis regimens consist of beta-lactam regimens directed against common GI and GU pathogens, which lack activity against Mycoplasma spp.

HIV-Associated Vacuolar Encephalomyelopathy.

We report a case of human immunodeficiency virus (HIV)-associated vacuolar encephalomyelopathy with progressive central nervous system dysfunction and corresponding vacuolar degeneration of the spinal cord, cranial nerves, and brain, the anatomic extent of which has not previously been described.

Cardiovascular Implantable Electronic Device Infections.

Infections associated with cardiac implantable electronic devices are increasing and are associated with significant morbidity and mortality. This article reviews the epidemiology, microbiology, and risk factors for acquisition of these infections. The complex diagnostic and management strategies associated with these serious infections are reviewed with an emphasis on recent updates and advances, as well as existing controversies. Additionally, the latest in preventative strategies are reviewed.

Short-Lasting Unilateral Neuralgiform Headache Attacks with Conjunctival Injection and Tearing in a Patient with Varicella-Zoster Virus Encephalomyelitis.

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing syndrome (SUNCT) is a type of trigeminal autonomic cephalalgia. Its etiology is generally idiopathic, though rarely it has been associated with viral infections. We describe the fourth case reported in the literature of SUNCT in association with viral meningoencephalitis.

Cefepime and Ceftazidime Safety in Hospitalized Infants.

BACKGROUND: Cefepime and ceftazidime are cephalosporins used for the treatment of serious Gram-negative infections. These cephalosporins are used off-label in the setting of minimal safety data for young infants. METHODS: We identified all infants discharged from 348 neonatal intensive care units managed by the Pediatrix Medical Group between 1997 and 2012 who were exposed to either cefepime or ceftazidime in the first 120 days of life. We reported clinical and laboratory adverse events occurring in infants exposed to cefepime or ceftazidime and used multivariable logistic regression to compare the odds of seizures and death between the 2 groups. RESULTS: A total of 1761 infants received 13,293 days of ceftazidime, and 594 infants received 4628 days of cefepime. Laboratory adverse events occurred more frequently on days of therapy with ceftazidime than with cefepime (373 vs. 341 per 1000 infant days, P < 0.001). Seizure was the most commonly observed clinical adverse event, occurring in 3% of ceftazidime-treated infants and 4% of cefepime-treated infants (P = 0.52). Mortality was similar between the ceftazidime and cefepime groups (5% vs. 3%, P = 0.07). There was no difference in the adjusted odds of seizure [odds ratio (OR) = 0.96 (95% confidence interval: 0.89-1.03)] or the combined outcome of mortality or seizures [OR = 1.00 (0.96-1.04)] in infants exposed to ceftazidime versus those exposed to cefepime. CONCLUSIONS: In this cohort of infants, cefepime was associated with fewer laboratory adverse events than ceftazidime, although this may have been due to a significant difference in clinical exposures and severity of illness between the 2 groups. There was no difference in seizure risk or mortality between the 2 drugs.