Candida infection of cerebrospinal fluid shunt devices: report of two cases and review of the literature

Implementation of an adapted perioperative ventriculoperitoneal shunting protocol in a tertiary center located in a low-to-middle-income country

OBJECTIVE

Preventative protocols have efficaciously reduced shunt infection in developed countries. However, the generalizability of these protocols in low-to-middle-income countries (LMICs) remains unclear. Previously, shunt insertion in the authors' center was routinely performed under institutional preventative precautions, which was updated via merging with the Hydrocephalus Clinical Research Network (HCRN) protocol. This study aimed to investigate the ventriculoperitoneal shunt (VPS) infection rates in pediatric patients following the implementation of the adapted protocol.

METHODS

The adapted protocol was implemented in all first-time VPS implantations between 2011 and 2021. The primary outcome was a 6-month shunt infection. The Pearson chi-square test was used for categorical variables and the Mann-Whitney U-test for numeric variables to evaluate the correlation with shunt infection.

RESULTS

A total of 352 first-time VPS procedures were performed adhering to the adapted protocol. The median age was 5 months, and 189 (53.7%) were male. Overall, 37 patients (10.5%) experienced shunt infection, with 30 (8.5%) occurring within the first 6 months, which was lower than 13.3% infection rate of the previous series of the same center. The infection rate was slightly higher than the 5.7% and 6.0% rates reported by HCRN studies. Patients with shunt infection were significantly younger (7.5 versus 17.5 months, P < 0.001).

CONCLUSIONS

This study validates the efficacy of an adapted perioperative protocol in mitigating shunt infection in a high-volume center in a LMIC. Adhering to a step-by-step protocol, modified to suit the healthcare resources and financial constraints of LMICs, could maintain low shunt infection rates that are roughly comparable to those of centers in high-income countries.

Candida meningitis/ventriculitis over a decade. Increased morbidity and length of stay a concern

AIM

The primary aim of this study was to review the diagnosis, management and outcome of Candida meningitis/ventriculitis in our hospital over a ten-year period.

MATERIALS AND METHODS

We retrospectively reviewed all culture and 18s rRNA nucleic acid positive CSF specimens processed between 1st January 2010 and 31st December 2020. Patient records were subsequently reviewed to assess the significance of the isolate.

RESULTS

Of 851 culture-positive cerebrospinal fluid (CSF) specimens, Candida spp. were isolated from 29 (3.4%), representing infection in 12 patients. One culture-negative specimen was positive for Candida on 18s rRNA testing. Of the 13 patients, eight were male; 61.5% and the median age was 47 years; range: 20-70. The median interval from admission to onset of infection and culture positivity was 24 days (range: 1-63 days). All patients had a central nervous system (CNS) device in situ (external ventricular drain: 11; ventriculoperitoneal shunt: 1; lumbar drain: 1). Four were colonised with Candida spp. before meningitis/ventriculitis diagnosis, from wounds (n = 3), respiratory (n = 3), and urine (n = 1) specimens. On culture, the most common species was Candida albicans (n = 8), followed by C. parapsilosis (n = 2), C. tropicalis (n = 1), and C. dubliniensis (n = 1). The median number of follow-up CSFs per patient was nine (range; 3-22), with a median of 6 days to CSF sterility (range 3-10 days). Treatment included; liposomal amphotericin B (n = 5), fluconazole (n = 2), liposomal amphotericin B, and flucytosine (n = 2), liposomal amphotericin B, fluconazole and flucytosine (n = 3), and intra-ventricular amphotericin B (n = 1). Median treatment duration was 25 days (range 11-76) and CNS device removal occurred in 12 patients. The median length-of-stay (LOS) was 58 days (range 24-406). On discharge, moderate to severe disability (Modified Rankin Scale [mRS] 3-5) was evident in eight patients. Two patients died and one was lost to follow-up.

CONCLUSION

Meningitis/ventriculitis due to Candida spp. is an uncommon but challenging infection, usually associated with a device, increased morbidity, LOS, and necessitating prolonged treatment. Neurosurgeons need to be aware of these issues in managing and in communicating with such complex patients.

Current research on fungi in chronic wounds

The occurrence of chronic wounds is a major global health issue. These wounds are difficult to heal as a result of disordered healing mechanisms. The most common types of chronic wounds are diabetic ulcers, pressure ulcers, arterial/venous ulcers and nonhealing surgical wounds. Although bacteria are an important cause of chronic nonhealing wounds, fungi also play a substantial role in them. The fungal infection rate varies with different chronic wound types, but overall, the prevalence of fungi is extremely underestimated in the clinical treatment and management of chronic wounds. Wounds and ulcers can be colonized by host cutaneous, commensal or environmental fungi and evolve into local infections, causing fungemia as well as invasive fungal disease. Furthermore, the fungi involved in nonhealing wound-related infections help commensal bacteria resist antibiotics and the host immune response, forcing wounds to become reservoirs for multiresistant species, which are considered a potential key factor in the microbial bioburden of wounds and ulcers. Fungi can be recalcitrant to the healing process. Biofilm establishment is the predominant mechanism of fungal resistance or tolerance to antimicrobials in chronic nonhealing wounds. Candida albicans yeast and Trichophyton rubrum filamentous fungi are the main fungi involved in chronic wound infection. Fungal species diversity and drug resistance phenotypes in different chronic nonhealing wound types will be emphasized. In this review, we outline the latest research on fungi in chronic wounds and discuss challenges and future perspectives related to diagnosing and managing chronic wounds.

Single and Repeated Episodes of Candida Species Isolated From Cerebrospinal Fluid for Diagnosing Probable Candida meningitis

Background: The clinical relevance of single or repeated episodes of Candida spp. in cerebrospinal fluid (CSF) in adult patients is debatable.

Methods: Forty-two patients with positive Candida episodes in CSF were enrolled in this retrospective study.

Results: A total of 42.9% (18/42) were determined to have probable Candida meningitis (PCM). Neurosurgery [odds ratio (OR) (95% confidence interval), OR: 14.4 (1.6–126.1), P = 0.004], lumbar drainage [OR: 5.8 (1.5–23.3), P = 0.009], VP shunt [(OR: 5.6 (1.2–25.8), P = 0.020)], external ventricular drainage [OR: 4.7 (1.3–17.7), P = 0.018], CRP ≥ 10.0 mg/L [OR: 4.9 (1.3–18.1), P = 0.034], and postsurgical broad-spectrum antibiotics [OR: 9.5 (1.8–50.5), P = 0.004] were risk factors associated with PCM. A single CSF Candida episode for the diagnosis of PCM had 7.7% (0.4–37.9%) sensitivity and 20.7% (8.7–40.3%) specificity, whereas repeated episodes of Candida had 66.7% (41.2–85.6%) sensitivity and 95.8% (76.9–99.8%) specificity. No significant difference was found in radiological imaging or CSF profiles between PCM and non-PCM patients. A total of 37.5% (9/24) of patients without PCM received empirical antifungal treatment, and 88.9% (16/18) of patients with PCM received preemptive antifungal treatment. PCM patients had hospitalized mortality rates of 50.0% (9/18). The odds ratio of mortality was 23.0 (2.5–208.6) for PCM patients compared with non-PCM patients (P = 0.001).

Conclusion: Both single and repeated positive CSF samples have low validity for the diagnosis of PCM, suggesting that novel strategies for diagnosis algorithms of PCM are urgently needed. Empirical antifungal treatment should be started immediately for suspicious patients with risk factors.

Central nervous system candidiasis beyond neonates: Lessons from a nationwide study

Though candidiasis is the most frequent invasive fungal infection, Candida spp. central nervous system (CNS) infections are rare but severe. To further describe clinico-patho-radiological presentations of this entity, we report a retrospective study from January 2005 to December 2018 including patients aged ≥ 28 days with proven or probable CNS candidiasis in France. Twenty-four patients were included. Seventeen patients (70%) had CNS localization secondary to disseminated candidiasis (10 with hematologic malignancies [HM]; the seven other patients had infective endocarditis [IE]). Among patients with HM, seven previously had lumbar puncture for intrathecal chemotherapy, the three others had IE. Among patients with disseminated infection, magnetic resonance imaging (MRI) evidenced meningitis (17%), micro-abscesses (58%), or vascular complications (67%). Seven patients (30%) had isolated CNS involvement related to neurosurgery (n = 2), CARD9 deficiency (n = 2), intravenous drug use, diabetes mellitus, or no identified predisposing condition (n = 1 each). All evaluated patients with isolated CNS involvement had meningitis on cerebrospinal fluid (CSF) and intracranial hypertension. For the latter patients, MRI evidenced meningitis (71%) or abscesses (57%). Among all patients, cerebrospinal fluid (CSF) culture grew Candida spp. in 31% of cases. CSF βDGlucan or mannan Ag were positive in respectively 86% and 80% of cases. Mortality attributed to CNS candidiasis was 42%: 53% in case of disseminated infection (70% for HM) and 14% in case of localized infection. CNS candidiasis are isolated or occur during disseminated infection in patients with HM and lumbar puncture for intrathecal chemotherapy or during IE. Clinical, radiological finding and outcome highly vary according to CNS localized versus disseminated candidiasis.

LAY SUMMARY

Candida is a yeast and is the most common cause of fungal infections worldwide. Candida central nervous system (CNS) infections are rare, severe, and poorly described. We report a retrospective study from January 2005 to December 2018 including patients aged ≥ 28 days with proven or probable CNS candidiasis in France. Twenty-four patients were included (14 men, median age 51 years). Seventeen patients had CNS localization secondary to disseminated candidiasis from blood to CNS (10 with hematologic malignancies [HM], the seven other patients had infective endocarditis [IE]). Seven patients had isolated CNS involvement related to neurosurgery (n = 2), CARD9 deficiency (n = 2), intravenous drug use (n = 1), diabetes mellitus (n = 1), or no identified risk factor (n = 1).During Candida CNS infections, brain lesions were meningitis abscesses or vascular complications. Cerebrospinal fluid (CSF) culture grew Candida spp. in 31% of cases. Forty-two percent of patients died from infection: 53% in case of disseminated infection (70% for HM) and 14% in case of localized infection.

Chronic Candida dubliniensis meningitis in a lung transplant recipient

Candida spp. are common colonizers of the oral mucosa and respiratory tract in lung transplant recipients. Although thought to be non-pathogenic in most cases, donor derived infections related to Candida spp. have been described. Among the manifestations of invasive candidiasis, chronic meningitis is one of the rarest and one of the most challenging to diagnose, due to the indolence of the disease and the low yield of the CSF cultures. It is associated with severe morbidity and a high mortality. Fungal PCR and BD glucan assays can be assistance in its diagnosis, although these tests are not widely available. We report a case of a possible donor derived Candida dubliniensis infection in a lung transplant recipient, who initially presented with empyema that was treated successfully, but subsequently developed chronic meningitis. Diagnosis was delayed due to the low yield of CSF cultures, and was confirmed with fungal PCR and BD glucan assay.

Fungal infections in pediatric neurosurgery

INTRODUCTION

Invasive mycosis of the central nervous system represent a diverse group of diseases that have gradually emerged as not only opportunistic infections in patients with immune susceptibility due to congenital and acquired deficiency, immunomodulation, solid organ and stem cell transplantation, hematological malignancies, and chronic steroid use but also in selected risk populations such as low weight preterm infants, patients with shunted hydrocephalus and external ventricular drainages, skull base surgery, and head injury.

OBJECTIVES

The purpose of this review is to familiarize the pediatric neurosurgeon with the most common mycosis and their clinical scenarios which can be encountered in the clinical practice, with special emphasis on clinical, radiological, and laboratory diagnosis beyond classical microorganism cultures as well as options in medical and surgical treatment given the high incidence of morbidity and mortality associated with these challenging entities.

METHODS

We conducted an online database review (Ovid, PubMed) gathering relevant English language literature published in the last 20 years with special emphasis on recent breakthroughs in the diagnosis and treatment of invasive mycosis of the CNS as well as reported cases within the pediatric neurosurgical literature and their surgical management.

RESULTS

Fungal agents capable of invading the CNS can behave as aggressive entities with rapid progression manifesting as overwhelming meningoencephalitis with vascular compromise or can lead to space-occupying lesions with abscess formation which require prompt diagnosis by either laboratory identification of the components of these biological agents and their host response or by obtaining tissue specimens for microbiological identification which may not be straightforward due to prolonged culture time.

CONCLUSION

Following a high degree of suspicion with prompt initiation of antifungal agents and reversal of potential immunosuppressant therapies along with neurosurgical evacuation of intracranial collections or removal of infected hardware (CSF shunts) can lead to more optimistic outcomes of these complex clinical scenarios.

Candida parapsilosis Infection of Ventriculoperitoneal Shunt in Adult: Case Report and Literature Review

BACKGROUND

Candida parapsilosis is an incredibly rare cause of ventriculoperitoneal (VP) shunt infections, with only 1 adult case reported in the literature to date.

CASE DESCRIPTION

We describe the case of a 45-year-old man admitted for a traumatic fall and subsequently treated with VP shunt placement for obstructive hydrocephalus secondary to a cerebellar contusion and intraventricular hemorrhage. Eight months following VP shunt placement, the patient presented with a 2-month history of clear fluid leakage through a dehiscent surgical abdominal wound overlying the distal VP shunt. Cerebrospinal fluid cultures were obtained and grew C. parapsilosis. The patient subsequently underwent VP shunt externalization and began antifungal treatment with intravenous liposomal amphotericin B. Cerebrospinal fluid studies continued to redemonstrate C. parapsilosis infection, for which VP shunt removal and external ventricular drain placement was performed. Three days into treatment with amphotericin B, he endured significant nephrotoxicity necessitating a switch to oral fluconazole. Following 3 weeks of oral fluconazole treatment with negative serial cerebrospinal fluid cultures, the patient underwent external ventricular drain removal and VP shunt insertion. Following the procedure and 22 total days of oral fluconazole treatment, our patient recovered well and was discharged to a rehabilitation facility in stable condition.

CONCLUSIONS

In our report, we describe the clinical course of our patient and offer a review and analysis of the most up-to-date literature concerning C. parapsilosis shunt infections, as well as treatment guidelines for central nervous system candidiasis.

Candida Meningitis After Transsphenoidal Surgery: A Single-Institution Case Series and Literature Review

Candida meningitis after neurosurgical procedures is a rare but potentially devastating complication. The presentation of meningitis can be insidious in immunosuppressed patients and thus can be easily overlooked. Cerebrospinal fluid studies often resemble bacterial profiles, and cultures can be falsely negative. Candida albicans is the most common species identified in postsurgical Candida meningitis, and delay in diagnosis and treatment can be devastating. The standard induction therapy for Candida meningitis has been amphotericin B combined with flucytosine. A high index of suspicion is needed in any patient with risk factors such as abdominal surgery, bowel perforation, recent broad spectrum antibiotic therapy, intravenous drug use, extremes of age, indwelling catheters, and immunosuppression such as AIDS, malignancy, antineoplastic therapy, and steroid use. Here, we describe 3 case presentations of patients with giant skull base tumors who developed postsurgical Candida meningitis, each with vastly different clinical courses and outcomes, ranging from benign to catastrophic. We performed a literature review with special focus on common risk factors, Candida species, diagnostic criteria, and treatment.

Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Central Nervous System Infections

Central nervous system (CNS) infections—i.e., infections involving the brain (cerebrum and cerebellum), spinal cord, optic nerves, and their covering membranes—are medical emergencies that are associated with substantial morbidity, mortality, or long-term sequelae that may have catastrophic implications for the quality of life of affected individuals. Acute CNS infections that warrant neurointensive care (ICU) admission fall broadly into three categories—meningitis, encephalitis, and abscesses—and generally result from blood-borne spread of the respective microorganisms. Other causes of CNS infections include head trauma resulting in fractures at the base of the skull or the cribriform plate that can lead to an opening between the CNS and the sinuses, mastoid, the middle ear, or the nasopharynx. Extrinsic contamination of the CNS can occur intraoperatively during neurosurgical procedures. Also, implanted medical devices or adjunct hardware (e.g., shunts, ventriculostomies, or external drainage tubes) and congenital malformations (e.g., spina bifida or sinus tracts) can become colonized and serve as sources or foci of infection. Viruses, such as rabies, herpes simplex virus, or polioviruses, can spread to the CNS via intraneural pathways resulting in encephalitis. If infection occurs at sites (e.g., middle ear or mastoid) contiguous with the CNS, infection may spread directly into the CNS causing brain abscesses; alternatively, the organism may reach the CNS indirectly via venous drainage or the sheaths of cranial and spinal nerves. Abscesses also may become localized in the subdural or epidural spaces. Meningitis results if bacteria spread directly from an abscess to the subarachnoid space. CNS abscesses may be a result of pyogenic meningitis or from septic emboli associated with endocarditis, lung abscess, or other serious purulent infections. Breaches of the blood–brain barrier (BBB) can result in CNS infections. Causes of such breaches include damage (e.g., microhemorrhage or necrosis of surrounding tissue) to the BBB; mechanical obstruction of microvessels by parasitized red blood cells, leukocytes, or platelets; overproduction of cytokines that degrade tight junction proteins; or microbe-specific interactions with the BBB that facilitate transcellular passage of the microorganism. The microorganisms that cause CNS infections include a wide range of bacteria, mycobacteria, yeasts, fungi, viruses, spirochaetes (e.g., neurosyphilis), and parasites (e.g., cerebral malaria and strongyloidiasis). The clinical picture of the various infections can be nonspecific or characterized by distinct, recognizable clinical syndromes. At some juncture, individuals with severe acute CNS infections require critical care management that warrants neuro-ICU admission. The implications for CNS infections are serious and complex and include the increased human and material resources necessary to manage very sick patients, the difficulties in triaging patients with vague or mild symptoms, and ascertaining the precise cause and degree of CNS involvement at the time of admission to the neuro-ICU. This chapter addresses a wide range of severe CNS infections that are better managed in the neuro-ICU. Topics covered include the medical epidemiology of the respective CNS infection; discussions of the relevant neuroanatomy and blood supply (essential for understanding the pathogenesis of CNS infections) and pathophysiology; symptoms and signs; diagnostic procedures, including essential neuroimaging studies; therapeutic options, including empirical therapy where indicated; and the perennial issue of the utility and effectiveness of steroid therapy for certain CNS infections. Finally, therapeutic options and alternatives are discussed, including the choices of antimicrobial agents best able to cross the BBB, supportive therapy, and prognosis.

Fungal infection of a ventriculoperitoneal shunt: histoplasmosis diagnosis and treatment

BACKGROUND

Histoplasmosis is a fungal disease caused by Histoplasma capsulatum, commonly found in the Americas, and Histoplasma duboisii, located in Africa. In the United States, H. capsulatum is prevalent in the Ohio and Mississippi river valleys. In rare circumstances, central nervous system (CNS) histoplasmosis infection can be caused by shunt placement. We present a case report of a 45-year-old woman in whom CNS histoplasmosis developed after having a ventriculoperitoneal (VP) shunt placed for communicating hydrocephalus. A review of the literature on fungal infections after CNS shunt placement as well as treatment options for this subset of patients was undertaken.

METHODS

The PubMed database current to 1958 was filtered and limited to English-language articles. Fifty-eight articles were selected for review based on evidence of information regarding the fungal organism responsible for shunt infection, symptoms, treatment, and/or outcomes. Also included in this review is our case study.

RESULTS

A thorough analysis of the PubMed database revealed 58 reported cases of CNS shunt-related fungal infections in the English-language medical literature as well as 7 therapeutic agents used to treat patients in whom postshunt fungal infections developed.

CONCLUSIONS

We describe the steps in diagnosis of histoplasmosis after shunt placement, provide an effective therapeutic regimen, and review the present understanding of CNS fungal infections. The medical literature was surveyed to compare and analyze various CNS fungal infections that can arise from shunt placement as well as treatments rendered.

Risk factors for recurrent shunt infections in children

Risk factors for recurrent shunt-related cerebrospinal fluid (CSF) infections were analyzed. A total of 58 children were treated for initial shunt infections (ISI): all children were treated with antibiotics and CSF drainage, either by removal of the shunt system and insertion of an external ventricular drainage (EVD) catheter (44 children, 75.9%) or by externalization of the existing ventricular catheter (14 children, 24.1%). Recurrent shunt infections (RSI) were detected in 15 children: nine had been treated with shunt removal and insertion of a new EVD catheter and six had been treated with externalization of the existing ventricular catheter. There was a statistically significant increase in the number of RSI in children treated with externalization of the existing ventricular catheter. Thus, to reduce the risk of RSI, total shunt removal and insertion of a new EVD catheter is preferred.

Candida infection of the central nervous system following neurosurgery: a 12-year review

BACKGROUND

Candida infection of the central nervous system (CNS) following neurosurgery is relatively unusual but is associated with significant morbidity and mortality. We present our experience with this infection in adults and discuss clinical characteristics, treatment options, and outcome.

METHODS

All episodes of Candida isolated from the central nervous system were identified by searching our laboratory database. Review of the cases was performed by means of a retrospective chart review.

RESULTS

Eleven episodes of Candida CSF infection following neurosurgery were identified over a 12-year period. Candida albicans was the predominant species isolated (n = 8, 73%). All infections were associated with foreign intracranial material, nine with external ventricular drains (82%), one with a ventriculoperitoneal shunt, one with a lumbar drain, and one with Gliadel wafers (1,3-bis [2-chloroethyl]-1-nitrosurea). Fluconazole or liposomal amphotericin B were the most common anti-fungal agents used. The mortality rate identified in our series was 27%.

CONCLUSIONS

Candida infection following neurosurgery remains a relatively rare occurrence but one that causes significant mortality. These are complex infections, the management of which benefits from a close liaison between the clinical microbiologist and neurosurgeon. Prompt initiation of antifungal agents and removal of infected devices offers the best hope of a cure.

Survey of fungi and yeast in polymicrobial infections in chronic wounds

OBJECTIVE

To assess the incidence, abundance and species diversity of fungi in chronic wounds, as well as to describe the associations of major fungi populations.

METHOD

Comprehensive molecular diagnostic reports were evaluated from a total of 915 chronic wounds in a retrospective study.

RESULTS

Of the 915 clinical specimens, 208 (23%) were positive for fungal species. These samples were further compared in a compiled dataset, and sub-classified among the four major chronic wound types (decubitus ulcer, diabetic foot ulcer, non-healing surgical wound, and venous leg ulcer). The most abundant fungi were yeasts in the genus Candida; however, Curvularia, Malessezia, Aureobasidium, Cladosporium, Ulocladium, Engodontium and Trichtophyton were also found to be prevalent components of these polymicrobial infections. A notable bacterial/fungal negative correlation was found to be apparent between Staphylococcus and Candida. There were also significant relationships between both bacterial and fungal genera and patient metadata including gender, diabetes status and cardiovascular comorbidities.

CONCLUSION

This microbial survey shows that fungi are more important wound pathogens and opportunistic pathogens than previously reported, exemplifying the impact of these under-reported pathogens. With the application of modern cost-effective and comprehensive molecular diagnostics, clinicians can now identify and address this significant component of chronic wound bioburden with targeted therapies, thereby improving healing trajectories.

Candida dubliniensis meningitis as delayed sequela of treated C. dubliniensis fungemia

We present a case of Candida dubliniensis meningitis that developed 2 months after apparently successful treatment of an episode of C. dubliniensis candidemia in a heart-lung transplant recipient in Australia. This case highlights the importance of follow-up in patients with candidemia or disseminated infection, especially in immunosuppressed patients.

Candida biofilms on implanted biomaterials: a clinically significant problem

In recent years there has been an increasing appreciation that microbial biofilms are ubiquitous, which has resulted in a number of studies on infectious diseases from a biofilm perspective. Biofilms are defined as structured microbial communities that are attached to a surface and encased in a matrix of exopolymeric material. A wide range of biomaterials used in clinical practice have been shown to support colonization and biofilm formation by Candida spp., and the increase in Candida infections in the last decades has almost paralleled the increase and widespread use of a broad range of medical implant devices, mainly in populations with impaired host defenses. Formation of Candida biofilms has important clinical repercussions because of their increased resistance to antifungal therapy and the ability of cells within biofilms to withstand host immune defenses. Further recognition and understanding of the role of Candida biofilms in human infection should help in the clinical management of these recalcitrant infections.

A Case of Ventricular Drainage Infection with a Rare Pathogen in Cerebrospinal Fluid: Vancomycin-Resistant Enterococcus faecium

The purpose of this study was to describe a patient, 7-month-old child with ventriculoperitoneal shunts for hydrocephalus with ventriculitis caused by vancomycin-resistant Enterococcus faecium. Two ventriculoperitoneal shunts were inserted just after birth and on the second month. On the sixth month, both shunts were removed because of dysfunction, and external drainage was inserted. The child developed fever, and lumbar puncture revealed a high leukocyte count and protein concentration after external drainage. Cerebrospinal fluid (CSF) cultures yielded E. faecium, which was resistant to ampicillin, erythromycin, gentamicin, penicillin G, vancomycin, and teicoplanin and was susceptible to chloramphenicol, ciprofloxacin, streptomycin, levofloxacin, and rifampin, as determined by the disk diffusion method. As a result of the antimicrobial susceptibility tests, multidrug antibiotic therapy was changed from vancomycin and ceftazidime to chloramphenicol, rifampin, and meropenem. In addition, a rifampin-clindamycin-impregnated shunt (The Codman Hakim Bactiseal, Raynham, MA) was inserted. The patient became afebrile, and CSF cultures were sterile after 15 days of yielding E. faecium. Implantation of the rifampin-clindamycin-impregnated shunt and timely use of appropriate antibiotics for 10 days according to antimicrobial susceptibility testing seem to be important in the resolution of vancomycin-resistant enterococci infections, especially in countries where linezolid and quinupristin-dalfopristin are not in use yet.

Invasive Candidiasis in Immunocompromised Hospitalized Patients

The frequency of infections by Candida species is increasing worldwide, with candidemia representing the fourth most common bloodstream infection in the U.S. The risk of infection is especially high in the immunocompromised, hospitalized patient. The treatment of and prophylaxis for Candida infection have led to the emergence of resistant species and the acquisition of resistance in previously susceptible species. Current therapeutic options include amphotericin B and its lipid compounds, fluconazole, itraconazole, voriconazole, and caspofungin. Research is focusing on better diagnostics and the evaluation of strategies such as prophylaxis in high-risk hosts and pre-emptive therapy.

Candida infections of medical devices

The number of indwelling medical devices is escalating, and an increasing proportion of device-related infections are being caused by Candida spp. Candida spp. produce biofilms on synthetic materials, which facilitates adhesion of the organisms to devices and renders them relatively refractory to medical therapy. Management of device-related Candida infections can be challenging. Removal of the infected device is generally needed to establish cure of Candida infections of medical devices. However, since the pathogenesis of Candida bloodstream infection is complicated, more studies are necessary to determine the role of catheter exchange in patients with both gastrointestinal tract mucositis and indwelling catheters. The medical and economic impact of these infections is enormous.

Candida species isolated from cerebrospinal fluid

In the period from November 1998 to June 2001 13 cases of nosocomial meningitis were reported. Candida albicans was isolated from 54% of the patients (7); C. parapsilosis from 23% (3); C. tropicalis from 15% (2) and C. krusei from 8% (1). C. albicans was isolated from the cerebrospinal fluid (CSF) of five children with the following diagnoses: nonspecified tumor of the central nervous system, Hodgkin's disease, meningitis, suspect neuroinfection, and sepsis. Examination of CSF allowed us to detect 2 strains of C. albicans from adult patients, one after neurosurgery because of a brain tumor and one with a vascular disease of the brain. C. parapsilosis was found in CSF from two premature children and one child with epilepsy. Two isolates of C. tropicalis were obtained from both blood and the CSF of a child from the neonatal intensive care unit and from a child from pediatric oncology with multiple malignant neoplasms. Only one strain of C. krusei was found in the oral cavity and CSF of a patient after neurosurgery performed after head trauma.

Neonatal Candida meningitis

Candida: spp. are becoming one of the most common pathogens associated with sepsis in the setting of neonatal intensive care. Invasive therapies aimed at improving patient survival, particularly among premature infants, contribute significantly to this alteration in the distribution of neonatal pathogens. Prematurity is one of the principle risk factors associated with the development of neonatal meningitis in this patient population. Untreated, neonatal candidal meningitis is associated with a poor outcome both in terms of morbidity and mortality. However, early diagnosis with timely initiation of antifungal therapy will improve outcome significantly. The following review outlines the pathogenesis, clinical features, diagnosis, and current treatment options for neonatal candidal meningitis.

Laboratory diagnosis of central nervous system infections

The laboratory diagnosis of CNS infection is essential for optimal therapy. Acute infection requires rapid turn-around testing with high predictive values, that is, the ability of a test to accurately identify those patients who do or do not have disease caused by a specific etiology. The Gram's stain, fungal stains of direct smears, antigen testing for C. neoformans, and culture of bacteria, fungi, mycobacteria, and some viruses are important tests for the diagnosis of acute infection. The laboratory diagnosis of chronic infection necessitates discussion between the clinician and laboratory technician to allow triaging of testing. Antigen tests for bacteria, fungi, and viruses; antibody tests for multiple microorganisms; and PCR testing for bacteria, M. tuberculosis, and many viruses are all important in limited clinical situations. All testing for acute or chronic disease depends on sufficient specimen that is transported to the laboratory in a manner that will not compromise viability or chemical integrity. Sterile containers that maintain moisture content, exclude oxygen for anaerobic requests, and are stored at proper temperatures (22 degrees C room, 4 degrees C refrigeration, or -20 degrees C freezer depending on pathogen and test) are mandatory. Many laboratory issues addressing the diagnosis of CNS infection are changing or evolving. Most important is the recognition that bacterial antigen testing for the diagnosis of acute bacterial meningitis rarely impacts patient management and is not routinely needed, CSF shunt infections differ from usual meningeal infections and require rapid diagnosis, and TB meningitis remains a difficult disease to diagnosis but may be confirmed first by PCR testing of CSF. In addition, Whipple's disease of the CNS can be confirmed using PCR with CSF; CJD has a marker protein, referred to as 14-3-3 antigen, that can be detected in CSF, and the diagnosis of fungal CNS disease requires careful interpretation of direct smears, antigen and antibody testing, and culture. Most difficult to diagnose among the CNS infections are viral meningitis and encephalitis. The appearance of new etiologies, such as West Nile virus, and the common use of PCR for the herpes viruses and enteroviruses represent important advances. Evolving methods for the laboratory diagnosis of CNS infection represent significant improvements over previous testing; however, the array of tests available demands more attention for appropriate selection, is significantly more expensive, and requires new skills for performance and interpretation. The responsibility for proper use of laboratory testing lies both with the clinician and laboratory technician.

Differential inhibition of growth hormone secretion by analogs selective for somatostatin receptor subtypes 2 and 5 in human growth-hormone-secreting adenoma cells in vitro

Somatostatin (SRIH), a cyclic tetradecapeptide hormone originally isolated from mammalian hypothalamus, is a potent suppressor of pituitary growth hormone (GH) secretion. SRIH acts through a family of G-protein-coupled membrane receptors containing seven transmembrane domains. Five genes encoding distinct SRIH receptor (SSTR) subtypes have so far been cloned in human and other species and termed SSTR1-5. In human somatotrophe pituitary adenomas GH secretion is controlled by both SSTR2 and SSTR5. However, in clinical practice only somatostatin analogs selective for SSTR2 (octreotide and lanreotide) are available. This may explain why clinical and in vitro responses to these analogs in acromegaly are only partial. In this study, we investigated the inhibitory effect of two new SRIH analogs with high selectivity for SSTR2 (NC-4-28B) and SSTR5 (BIM-23268) and compared it to that of native somatostatin (SRIH-14) on a large number of GH-secreting adenomas obtained by transphenoidal neurosurgery. Tissues from 16 adenomas were enzymatically dispersed and plated in 24-well dishes at 50,000 cells/well. After 3 days, groups of three wells were incubated for 4 h with medium alone, SRIH-14 or analogs NC-4-28B or BIM-23268, at the concentrations of 0.01, 0.1 and 1 microM. Our results show that 9 out of 16 adenomas were responsive (GH suppression: 20-40% vs. control, p < 0.05) to SRIH. In this group only 4 adenomas showed similar responses to both selective analogs, with 2 nonresponders (expression of other SRIH receptor subtypes) and 2 responders (concomitant expression of SSTR2 and SSTR5) to both analogs. GH release was selectively inhibited by NC-4-28B in 3 adenomas and by BIM-23268 in the remaining 2 adenomas, suggesting predominant expression of SSTR2 and SSTR5, respectively. SRIH failed to inhibit GH release in 7 adenomas (43%). Interestingly, in that group a better inhibitory effect was obtained with BIM-23268 (5 out of 7 adenomas) than with NC-4-28B, suggesting expression of a few SSTR5 receptors only, or of both SSTR2 and SSTR5, respectively. We conclude that the availability of somatostatin analogs selective for SSTR5 will enhance the treatment potency and spectrum in acromegaly.