Multidrug-resistant Acinetobacter baumannii ventriculitis: successful treatment with intraventricular colistin.

Acinetobacter baumannii has emerged as an important nosocomial pathogen that can cause a multitude of severe infections. In neurosurgical patients the usual presentation is ventriculitis associated with external ventricular drainage. Carbapenems have been considered the gold standard for the treatment of Acinetobacter baumannii ventriculitis, but resistant isolates are increasing worldwide, reducing the therapeutic options. In many cases polymyxins are the only possible alternative, but their poor blood-brain barrier penetration could require them to be directly administered intraventricularly and clinical experience with this route is limited. We review the literature concerning intraventricular use of colistin (polymyxin E) for A. baumannii ventriculitis and add three cases successfully treated with this method. Our experience suggests that intraventricular colistin is a potentially effective and safe therapy for the treatment of multidrug-resistant A. baumannii central nervous system infections.

[Brain abscess in a third-level hospital: epidemiology and prognostic factors related to mortality]. / Abscesos cerebrales en un hospital de tercer nivel: epidemiología y factores que influyen en la mortalidad.

OBJECTIVE: To document the epidemiology, causes, treatment and prognostic factors associated with mortality of patients with brain abscess in a tertiary medical center. METHODS: Observational retrospective cohort study of patients with cerebral abscess admitted at a tertiary hospital during 13 years. RESULTS: The case records of 71 patients admitted to a tertiary hospital between January 1992 and December 2005 and diagnosed of brain abscess were review. Brain abscess occurred at all ages, more frequently in men than in women. Fever, headache and altered mental status were common presenting symptoms. The most common site of infection was the frontal lobe (28 patients). Seventeen patients had multiple abscesses. Staphylococcal infection was seen most commonly. Computed tomography provided sufficient diagnostic information in all cases. Twenty six patients had early surgical drainage. Thirty four patients were admitted to the intensive care Unit (ICU). The overall mortality was 21% (15 patients), all of that related to the infection. Six patients died in ICU. More than 65 years of age (OR, 1.0; CI 95%, 1.0-1.1), medical treatment without surgery (OR, 8.9; CI 95%, 1.1-73.8), presence of multiple abscesses, (OR, 6.0; CI 95%, 1.0-34.9), immunosuppression (OR, 21.5; CI 95%, 2.9-157.2) and delay in starting antibiotherapy (OR, 1.5 per day of delay; CI 95%, 1.0-2.1) were independent predictors of in-hospital death. CONCLUSIONS: In spite of improvement in diagnosis and treatment of patients with cerebral abscess, mortality is still high. Factors related to patient underlying diseases and the delay in the start an antibiotic treatment were associated with increased mortality (50% increase of mortality risk per day in the delay of starting antibiotherapy).

Evaluation of the Duke criteria in 93 episodes of prosthetic valve endocarditis: could sensitivity be improved?

BACKGROUND: Since publication of the Duke criteria for diagnosing endocarditis, several articles have confirmed their sensitivity when native and prosthetic valves are considered together. OBJECTIVES: To compare the differences between the older von Reyn criteria and the Duke criteria in prosthetic valve endocarditis only, and to determine if the latter's sensitivity could be improved by adding 2 minor criteria: new-onset heart failure and presence of conduction disturbances. METHODS: We retrospectively evaluated 93 episodes of prosthetic valve endocarditis from January 1986 to January 1998 in a teaching hospital, and then analyzed the 76 surgically confirmed episodes to compare the differences between the von Reyn and Duke diagnostic criteria. RESULTS: The von Reyn criteria rejected the diagnosis in 16 of the confirmed episodes, compared with 1 diagnosis missed by the Duke criteria and 1 missed using our suggested modifications. Definite diagnosis (Duke) was established in 60 episodes, compared with a diagnosis of probable (von Reyn) in 36 episodes (P<.001). Our modifications improved the sensitivity of the Duke criteria, diagnosing 70 episodes as definite (P = .02). CONCLUSIONS: As was the case with native valve endocarditis, the Duke criteria proved to be more sensitive than the von Reyn criteria in prosthetic valve endocarditis. The addition of 2 minor criteria (new-onset heart failure and presence of conduction disturbances) could improve the diagnostic sensitivity of the Duke criteria.

[Clinico-epidemiologic manifestations of progressive multifocal leukoencephalopathy in patients with acquired immunodeficiency syndrome (AIDS)]. / Manifestaciones clínico-epidemiológicas de la leucoencefalopatía multifocal progresiva en pacientes con síndrome de inmunodeficiencia adquirida (SIDA).

BASIS: Severely immunosuppressed patients, including those with AIDS in advanced stage, can suffer opportunistic infections, between them PML. The purpose of this study is to determine epidemiological, clinical and neuroradiological parameters of HIV infected patients diagnosed of PML. METHOD: Retrospective review of clinical histories and clinical as well as radiological characteristics, of seven patients diagnosed of AIDS and PML in the Infectious Diseases Unit of our center between January 1990 and December 1997. RESULTS: Seven patients out of 1093 HIV infected patients were diagnosed of PML (0.76%). All of them were male, intravenous drug users, with a mean age of 32.1 years. Five patients were diagnosed before 1994. In four cases PML was the first opportunistic infection. The mean survival time was 119 +/- 82.2 days (27-231 days). At the moment of diagnosis four patients (57.1%) showed cerebellar symptoms, three (42.8%) sensory deficits and two (28.5%) cognitive dysfunction. There were multiple neurological symptoms in five cases. The mean CD4 cell count was 63.4 cells/mm3. None of the patients showed other concomitant opportunistic infections neither disturbances of cerebrospinal fluid (CSF). CT and NMR showed typical lesions in frontal lobe and cerebellum in four patients. Other affected areas were occipital and parietal lobe, basal ganglia and brain stem. The diagnosis of PML was established by clinical and neuroradiological criteria in six patients and by autopsy in one patient. CONCLUSIONS: The diagnosis of PML in HIV infected patients can be made by clinical and neuroradiological criteria. In the last years, and probably due to the new antiretroviral agents, it has been observed a decrease of the PML incidence in these patients. Nevertheless its prognosis is still dreadful and at present there is no specific curative treatment.

[The action of naloxone on monocyte chemotaxis in heroin addicts]. / Acción de la naloxona sobre la quimiotaxis monocitaria de heroinómanos.

Intravenous (I.V.) drug users possess a decrease of the monocyte chemotaxis directly related to drug usage. We study the effects of naloxone on monocyte chemotaxis in I.V. drug users, evaluating the chemotactic index and the cellular level of cAMP. The incubation of monocytes with naloxone did not modify the chemotactic index nor the cellular levels of cAMP, the first remaining low and the second high, this being statistically significant compared with the control group. We comment on the possible causes of naloxone's lack of effect and we suggest the role of cAMP in causing the chemotactic defect in this group of patients.

[HIV infection and monocyte function]. / Infección por VIH y función monocitaria.

An study of the non-specific function of monocyte in 14 IVDU (intravenous drug-users) was carried out in order to assess the role of HIV in the pathogenesis of monocyte function alteration in this population. Two separate groups were formed depending on whether they were infected with HIV or not. In comparison with the control group, the decreases of the adherence and of chemotaxis found were similar to that previously described. No differences were observed between both groups. Finally, the meaning of these results is discussed.

Cutaneous mucormycosis: report of five cases and review of the literature.

Mucormycosis is a highly aggressive fungal infection caused by Zygomycetes, from the order of Mucorales. This infection commonly presents an aggressive and rapid course and typically affects immunocompromised patients. Mucormycosis can manifest in different clinical patterns and locations. Although the correct diagnosis is often difficult, an early identification is essential for patient survival. Several clinical forms of mucormycosis are recognised. Cutaneous mucormycosis is less common than other clinical forms, but potentially lethal if treatment is not rapid. Tissue examination by histopathology and culture confirms the fungal infection. Standard treatment includes antifungal therapies associated with surgical debridement. We report five different cases of cutaneous mucormycosis treated in our institution and the management carried out in each case.

Clinical and microbiological characteristics of 28 patients with Staphylococcus schleiferi infection.

The aim of this study was to analyse the clinical and microbiological characteristics of a series of patients with infection by Staphylococcus schleiferi. Seventy-one isolates were recovered from 36 patients between January 1993 and June 1999 at a tertiary care centre in northern Spain. There were 28 patients with well-documented clinical data. Infection was more frequent in men (89.3%), and more than half of the patients had some degree of immunosuppression, mainly malignant neoplasms. Infection was nosocomial in 22 cases and community-acquired in the remaining cases. Staphylococcus schleiferi was frequently associated with wound infections, mainly surgical-site infections, although unusual types of infections were detected. Infection-related mortality was low. This study highlights the importance of careful identification of Staphylococcus schleiferi in the clinical microbiology laboratory. Due to the documented association of Staphylococcus schleiferi with clinical infections in humans, any isolates of this organism should be assumed to be pathogenic, unless proven otherwise.

Candidemia in a tertiary care hospital: epidemiology and factors influencing mortality.

The present study was conducted in order to assess the epidemiology and clinical course of candidemia and to identify the risk factors associated with mortality. A total of 143 episodes of nosocomial candidemia were identified during a 5-year period, and these were included in the study. The majority of candidemic episodes were due to Candida albicans (63, 44%), followed by Candida parapsilosis(32, 22%). The overall mortality was 45%. The following independent prognostic factors for mortality were identified: bacterial sepsis, rapidly fatal illness, chronic obstructive lung disease, presence of a central venous catheter, candidemia due to Candida albicans, and lack of antifungal therapy.

Opioids depress in vitro human monocyte chemotaxis.

Intravenous drug abusers (IDA) normally show functional defects in monocyte activity, in particular their chemotactic response. The aim of the present work was to study the action of several opioids on monocyte chemotaxis. To do so, monocytes from healthy individuals were incubated with heroin and morphine at three different concentrations (10(-5) M, 10(-6) M and 10(-7) M), with the finding of a significant depression in monocyte chemotaxis in all cases. This alteration could be due to a receptor effect or, conversely, to a non-specific effect. Accordingly, in the second phase of the study, monocytes from controls were incubated with a selective agonist of mu receptors (DAGO) and a selective agonist of delta receptors (DPDPE). In both cases a decrease in chemotactic function was observed similar to that following incubation with morphine or heroin. Preincubation of the monocytes with naloxone prevented the depression induced by both specific agonists. These findings suggest that opioids play an important role in the depression of monocyte chemotaxis observed in IDA. The results also suggest the presence of mu and delta opiate receptors in the cells of the phagocytic mononuclear system.

Prognostic factors for pneumococcal bacteremia in a university hospital.

The records of adult patients with pneumococcal bacteremia who were seen over an 8-year-period at an 1,100-bed university teaching hospital were reviewed in order to revise the clinical and laboratory findings and to identify the risk factors associated with mortality. A total of 156 patients were studied, 101 men and 55 women. The mean age of the patients was 65 years. Eighty-seven percent of the patients had community-acquired bacteremia and 13% had nosocomial pneumococcal bacteremia. The overall mortality was 33.9% and the related mortality was 20.5%. The following factors were associated with an increased risk of adverse outcome in the univariate analysis: mechanical ventilation (risk ratio [RR]=3.40; 95% confidence interval [95% CI]=1.44-8.05), administration of parenteral nutrition (RR=3.40; 95% CI =1.44-8.05), and the presence of an intravenous catheter (RR=2.33; 95% CI=1.27-4.24). In the multivariate analysis, the independent prognostic factors for mortality were as follows: development of clinical complications during the episode of bacteremia, rapidly fatal illness, advanced age and administration of parenteral nutrition. The results suggest that the overall mortality due to pneumococcal bacteremia continues to be high. Four independent risk factors associated with increased mortality were identified. Prevention and immunization with polyvalent pneumococcal polysaccharide vaccine should be practiced more widely.

Acinetobacter bacteraemia in a teaching hospital, 1989-1998.

Background: The mortality rate from bacteraemia is one of the highest among infections in hospitals, especially in the intensive care unit (ICU). Recently, an increase in nosocomial bacteraemia caused by gram-negative resistant pathogens has been observed. In this work we review the clinical and laboratory findings of adult patients with Acinetobacter bacteraemia in order to identify risk factors associated with mortality. Methods: A retrospective review of the medical records of patients with Acinetobacter bacteraemia identified by blood cultures from the Diagnostic Microbiology Laboratory was conducted between January 1989 and March 1998. Results: We identified 59 cases of Acinetobacter bacteraemia. Most of the infections (71%) were nosocomial; the majority occurred in the Department of Internal Medicine (28.8%), followed by Haematology (27%) and the ICU (23%). A. lwoffii was isolated in 52.5% of cases and A. baumannii in 47.5%. The related mortality was 17%. Staying in the ICU was associated with A. baumannii bacteraemia (P<0.004). An intravascular catheter was the leading source of infection (37%). Main risk factors were mechanical ventilation (28%), parenteral nutrition (23%) and the presence of a urinary catheter (22%). In the multivariate analysis the independent prognostic factors for mortality were the presence of shock (P<0.05) and the severity of the underlying disease, according to the classification of McCabe (P<0.05). Conclusions: The incidence of Acinetobacter bacteraemia has increased in the last decade, mainly since 1995. The development of septic shock and the severity of the underlying disease appear to be associated with an increase in mortality.

Depression of monocyte chemotaxis in intravenous drug abusers (IDA): cell alteration.

Intravenous drug abusers (IDA) show an important immunological dysfunction that plays a key role in pathogenesis of infections found in these patients. A defective adherence and chemotaxis has been described at the level of mononuclear phagocytic system (MPS). In this paper, we center on defective chemotaxis. In the face of a chemotactic alteration, the first step is trying to locate the alteration as humoral or cellular; we have used the work sheme proposed by Yousif-Kadaru. Serum of IDA and controls, E. Coli endotoxin-activated and non-activated were used as attractants. Chemotaxis was studied by the morphologic method of Snyderman. Attractant capacity of E. Coli endotoxin activated serum was 55.93 +/- 10.88, similar to that of controls, 59 +/- 10.58. The same was true for non-activated serum, 42.5 +/- 16.8 compared to 44.67 +/- 19.54. That means, according with the scheme proposed, that the alteration is localized in the cell. Some factors that could participate in the pathogenesis of the motor defect are commented in the discussion. The elevation in immunocomplexes titer observed in IDA could depress monocyte chemotaxis, but the defect would be humoral. A deficit in chemotactic factor could be discarded because its production capacity is preserved in IDA. Liver disease, both acute and chronic, is one of the most frequent medical complications in these patients. The cellular localization of depression eliminates any participation in the pathogenesis of chemotactic alteration.

Leukocyte chemotaxis.

Monocyte chemotaxis is a function of mononuclear phagocytic system cells that enables migration toward the focus of infection and inhibition of microorganism growth and proliferation. In this paper we review the chemotactic phenomena following Becker's scheme that distinguishes three phases: recognition, transduction and the effector phase. The recognition phase is comprised of the interaction of a chemotactic agent with a receptor located on the cell surface. We cite the multiple chemoattractant presently known, and the mechanisms that regulate this phase, "up-regulation" and "down-regulation" phenomena, and the presence of receptors in low and high-affinity states. The transduction phase comprises all biochemical events produced after internalization of the attractant-receptor complex, whose purpose is triggering the cell motor apparatus. The key event in beginning movement is the increase of cytosol calcium. Alterations in membrane phosphoinositols constitute the initial transductor mechanism in chemotaxis, inositol-triphosphate and diacylglycerol behaving as second messengers. We review the diverse functions of these phospholipids, as well as we do a graphic representation of these (fig 1). Motor phase comprises the movement of the cell toward the chemotactic gradient through activation of the motor cell apparatus. We describe the intervening elements, actin and its regulatory proteins acumentin and gelsolin, actin-fixing protein, myosin and microtubuli, and the four phases of locomotion mechanism: reversible adherence, pseudopode emission, cell polarity and movement that results from an alternance between gel and sol states.