Effect of dietary supplementation of Bifidobacterium and Lactobacillus strains in Apis mellifera L. against Nosema ceranae

Nosema ceranae is a widespread microsporidium of European honeybee Apis mellifera L. affecting bee health. The ban of Fumagillin-B (dicyclohexylammonium salt) in the European Union has driven the search for sustainable strategies to prevent and control the infection. The gut microbial symbionts, associated to the intestinal system of vertebrates and invertebrates and its impact on host health, are receiving increasing attention. In particular, bifidobacteria and lactobacilli, which are normal inhabitants of the digestive system of bees, are known to protect their hosts via antimicrobial metabolites, immunomodulation and competition. In this work, the dietary supplementation of gut bacteria was evaluated under laboratory conditions in bees artificially infected with the parasite and bees not artificially infected but evidencing a low natural infection. Supplemented bacteria were selected among bifidobacteria, previously isolated, and lactobacilli, isolated in this work from healthy honeybee gut. Four treatments were compared: bees fed with sugar syrup (CTR); bees fed with sugar syrup containing bifidobacteria and lactobacilli (PRO); bees infected with N. ceranae spores and fed with sugar syrup (NOS); bees infected with N. ceranae and fed with sugar syrup containing bifidobacteria and lactobacilli (NP). The sugar syrup, with or without microorganisms, was administered to bees from the first day of life for 13 days. N. ceranae infection was carried out individually on anesthetised 5-day-old bees. Eight days after infection, a significant (P<0.05) lower level of N. ceranae was detected by real-time PCR in both NP and PRO group, showing a positive effect of supplemented microorganisms in controlling the infection. These results represent a first attempt of application of bifidobacteria and lactobacilli against N. ceranae in honeybees.

Increasing pathomorphism of pulmonary tuberculosis: an observational study of slow clinical, microbiological and imaging response of lung tuberculosis to specific treatment. Which role for linezolid?

During recent years, a progressive emerging of tuberculosis occurred, related to the overall increased age of general population, primary and secondary (iatrogenic) immunodeficiencies, the availability of invasive procedures, surgical interventions and intensive care supports, bone marrow and solid organ transplantation, and especially the recent immigration flows of people often coming from areas endemic for tuberculosis, and living with evident social-economical disadvantages, and with a reduced access to health care facilities. Since January 2006, at our reference centre we followed 81 consecutive cases of pulmonary tuberculosis, with 65 of them which remained evaluable for the absence of extrapulmonary complications, and a continuative and effective clinical and therapeutic follow-up. The majority of episodes of evaluable pulmonary tuberculosis (49 cases out of 65: 75,4%) occurred in patients who immigrated from developing countries. In two patients multiresistant (MDR) Mycobacterium tuberculosis strains were found, while two more subjects (both immigrated from Eastern Europe) suffered from a disease due to extremely resistant (XDR) M. tuberculosis strains. Although enforcing all possible measures to increase patients' adherence to treatment (empowerment, delivery of oral drugs under direct control, use of i.v. formulation whenever possible), over 72% of evaluable patients had a very slow clinical, microbiological, and imaging ameliorement (1-6 months), with persistance of sputum and/or bronchoalveolar lavage (BAL) fluid positive for M.tuberculosis microscopy and/or culture for over 1-4 months (mean 9.2+/-3.2 weeks), during an apparently adequate treatment. When excluding patients suffering from XDR and MDR tuberculosis, in four subjects we observed that off-label linezolid adjunct together with at least three drugs with residual activity against tuberculosis, led to a significantly more rapid clinical-radiological improvement and negative microbiological search, with consequent possibility to led to a protected discharge, supported by a sequential, oral therapy. Linezolid was also successfully employed in all the four patients with XDR or MDR pulmonary tuberculosis: among these patients, a definitive or temporarily negativization of respiratory secretions, and consequent discharge, was achieved only after linezolid adjunct. Notwithstanding the maintained microbiological susceptibility of M. tuberculosis strains responsible of the great majority of cases of pulmonary tuberculosis to first-line drugs, an unexpected tendency of patients to have a persistingly positive sputum and/or BAL, and to experience prolonged hospitalization for cure and isolation, has been recognized in the last years. No particularly suggestive radiological imaging seems predictive of a so prolonged course, so that we presently lack of clinical and imaging elements which may be predictive of this slow treatment response. The same is for demographic and epidemiological issues, eventual underlying diseases, and clinical presentation, so that a major problem for health care providers is to distinguish upon admission patients who will be prone to have slow therapeutic response and a related prolonged hospitalization. The novel oxazolidinone linezolid is characterized by an affordable in vitro activity against M. tuberculosis, and an extremely elevated intracellular concentration in respiratory tissues. Worldwide, increasing microbiological, pharmacological, and clinical evidences may recommend the use as linezolid adjunct as an off-label salvage treatment of pulmonary tuberculosis refractory to treatment, although not necessarily determined by resistant (MDR-XDR) M. tuberculosis strains. Randomized clinical trials including initially patients with ascertained chemioresistant tuberculosis, are strongly warranted.

An active microbiological surveillance project at an Italian teaching hospital: microbial isolates, recent epidemiological trends, major clinical concerns, and antimicrobial susceptibility rates during a four-year period

A microbiological surveillance program is currently performed at our tertiary-care teaching hospital. The temporal trend of microbial isolates from patients admitted during four calendar years (2004 to 2007) was analyzed according to the main bacterial and fungal culture organisms. The same pathogens isolated more than once from the same patient within one month were considered only once. On the whole, the main pathogen group remained that of Enterobacteriaceae (6,608 isolations out of 19,666: 33.6%, with Escherichia coli found in 60-75% of cases), with no significant difference over time. Staphylococci (4,150 isolates), and enterococci (3,276 isolates) were the two largest groups after Enterobacteriaceae, but staphylococci significantly declined during the four-year period (p .001), mainly due to progressively reduced isolation of coagulase-negative staphylococci. By contrast, a slight increase in enterococci occurred (p .05). Based on the frequency of isolation, Gram-negative oxidase-positive organisms accounted for 2,109 episodes, followed by other aerobic Gram-positive organisms other than Staphylococci-Enterococci (613 isolates), and anaerobes (583 isolates): no significant variations occurred over time for these last microbial groups. With regard to Gram-negative oxidase-negative microorganisms (567 isolates), non-beta-haemolytic streptococci (464 cases) and beta-haemolytic streptococci (260 isolates), a significant reduction of frequency occurred from 2004 to 2007 (p.05 to p.001). Finally, fungal infections accounted for 1,036 overall episodes, in over 80% of cases represented by Candida spp. Prospective microbiological monitoring is expected to contribute significantly to our knowledge of local epidemiological figures and antimicrobial sensitivity profile of hospital infections, and plays a major role in selecting both treatment and chemoprophylaxis schedules, especially on a local-regional basis. Although the major causative agents of in-patient infections remain Enterobacteriaceae, a significant decline in coagulase-negative Staphylococci, all Streptococci, and Gram-negative oxidase-negative organisms occurred over the four-year period, while Enterococci showed a mild increase over time.

Effect of early antibiotic prophylaxis with ertapenem and meropenem in experimental acute pancreatitis in rats

BACKGROUND

The clinical course in acute necrotizing pancreatitis is mainly influenced by bacterial infection of pancreatic and peripancreatic necrosis. The effect of two antibiotic treatments for early prophylaxis was studied in the taurocholate model of necrotizing pancreatitis in the rat.

METHODS

Sixty male Sprague-Dawley rats were divided into three pancreatitis groups (15 animals each) and a sham-operated group (15 animals, control group). Pancreatitis was induced by intraductal infusion of 3% taurocholate under sterile conditions. Animals were placed on one of two different antibiotic regimens (15 mg/kg ertapenem or 20 mg/kg meropenem, one shot) after the induction of pancreatitis or received no antibiotics (control). All animals were sacrificed after 24 h to study pancreatic and extrapancreatic infection.

RESULTS

Early antibiotic prophylaxis with either erapenam or meropenem significantly decreased pancreatic infection from 12/15 (control group) to 4/15 (ertapenem antibiotic group) and 3/15 (meropenem antibiotic group) (P < 0.05).

CONCLUSIONS

In our animal model of necrotizing pancreatitis, early antibiotic prophylaxis with ertapenem and meropenem reduced bacterial infection of the pancreas. The efficacy of early antibiotic prophylaxis with ertapenem in the clinical setting should be subject to further research.

Successful treatment of multi-resistant Pseudomonas aeruginosa osteomyelitis after allogeneic bone marrow transplantation with a combination of colistin and tigecycline

A case of osteomyelitis caused by multidrug-resistant Pseudomonas aeruginosa is reported in a patient who underwent allogeneic bone marrow transplantation for acute lymphoblastic leukaemia. The patient was successfully treated by prolonged administration of a full dose of colistin and tigecycline, and surgical curettage with the positioning of resorbable calcium sulfate pellets loaded with colistin.

A puzzling microbiological and clinical discrepancy in the management of acute, severe skin-soft tissue and joint staphylococcal infection. In vitro antimicrobial susceptibility to glycopeptides, versus in vivo clinical efficacy of linezolid alone

We present an intriguing case report of a septicemic post-elective surgical staphylococcal knee arthritis and cellulitis which did not respond to long-term courses of associated rifampicin and teicoplanin or vancomycin despite apparently favourable in vitro susceptibility assays, but rapidly resolved after i.v. followed by oral administration of linezolid. The lack of response to a two-week course of glycopeptides cannot be explained by the in vitro mimimum inhibitory concentrations (MIC90) of involved organisms, which showed full susceptibility of Staphylococcus aureus to vancomycin and teicoplanin, and sensitivity of an accompanying Staphylococcus epidermidis isolated from blood cultures to vancomycin and rifampicin, with borderline "intermediate" values found for teicoplanin. Since neither abscess formation nor bone involvement were of concern, effective glycopeptide and rifampicin penetration into infectious tissue should have been ensured. From a clinical point of view, only the introduction of a two-week i.v. linezolid followed by one more week of oral linezolid obtained a complete clinical and microbiological cure, and an unhoped-for functional success. When managing severe multiresistant gram-positive infections, in vitro activity should be carefully evaluated against expected drug penetration rates into the relevant infectious tissues.

Resolution of a Pseudomonas aeruginosa outbreak in a hematology unit with the use of disposable sterile water filters

We observed a significant increase of Pseudomonas aeruginosa bacteremias during 2002. Eighty-five microbiological samples were taken from different potential sources of infection. Twenty-nine out of 46 specimens obtained from water taps, shower heads and siphons tested positive for Pseudomonas aeruginosa. Weekly pharyngeal and rectal swabs in high risk patients, use of tap water after running the tap for at least 5 minutes and use of weekly disposable sterile filters in all taps and showers resulted in a significant decrease in Pseudomonas aeruginosa bacteremias. Moreover, we observed a significant reduction in Pseudomonas aeruginosa-positive surveillance cultures after implementation of these measures.

Artificial Intelligence Techniques for Monitoring Dangerous Infections

The monitoring and detection of nosocomial infections is a very important problem arising in hospitals. A hospital-acquired or nosocomial infection is a disease that develops after admission into the hospital and it is the consequence of a treatment, not necessarily a surgical one, performed by the medical staff. Nosocomial infections are dangerous because they are caused by bacteria which have dangerous (critical) resistance to antibiotics. This problem is very serious all over the world. In Italy, almost 5-8% of the patients admitted into hospitals develop this kind of infection. In order to reduce this figure, policies for controlling infections should be adopted by medical practitioners. In order to support them in this complex task, we have developed a system, called MERCURIO, capable of managing different aspects of the problem. The objectives of this system are the validation of microbiological data and the creation of a real time epidemiological information system. The system is useful for laboratory physicians, because it supports them in the execution of the microbiological analyses; for clinicians, because it supports them in the definition of the prophylaxis, of the most suitable antibi-otic therapy and in monitoring patients' infections; and for epidemiologists, because it allows them to identify outbreaks and to study infection dynamics. In order to achieve these objectives, we have adopted expert system and data mining techniques. We have also integrated a statistical module that monitors the diffusion of nosocomial infections over time in the hospital, and that strictly interacts with the knowledge based module. Data mining techniques have been used for improving the system knowledge base. The knowledge discovery process is not antithetic, but complementary to the one based on manual knowledge elicitation. In order to verify the reliability of the tasks performed by MERCURIO and the usefulness of the knowledge discovery approach, we performed a test based on a dataset of real infection events. In the validation task MERCURIO achieved an accuracy of 98.5%, a sensitivity of 98.5% and a specificity of 99%. In the therapy suggestion task, MERCURIO achieved very high accuracy and specificity as well. The executed test provided many insights to experts, too (we discovered some of their mistakes). The knowledge discovery approach was very effective in validating part of the MERCURIO knowledge base, and also in extending it with new validation rules, confirmed by interviewed microbiologists and specific to the hospital laboratory under consideration.

Epidemiological, clinical and therapeutic features of AIDS-related Mycobacterium kansasii infection during the HIV pandemic: an 11-year follow-up study

OBJECTIVES

Optimal diagnosis and timely treatment of atypical mycobacteriosis, and especially Mycobacterium kansasii disease, remain a serious challenge for clinicians engaged in the management of the immunocompromised host.

METHODS AND RESULTS

From more than 2700 hospitalizations (over 1800 patients) attributable to HIV-associated disorders over an 11-year period, 12 patients were found to have a confirmed M. kansasii infection. This reflects the recent reduction in the frequency of this HIV-related complication, which virtually disappeared after the introduction of potent antiretroviral combinations in 1996. In the early 1990s, the lack of effective antiretroviral regimens made frequent the association with AIDS, a mean CD4 lymphocyte count of nearly 20 cells/microL, and an extremely variable chest X-ray features. The recent detection of a further case was attributable to late recognition of very advanced HIV disease, complicated by multiple opportunistic disorders.

CONCLUSIONS

Mycobacterium kansasii respiratory or disseminated infection continues to occur, and poses diagnostic problems in terms of late or missed identification as a result of slow culture and frequently concurrent opportunistic disease. Serious therapeutic difficulties also arise from the unpredictable in vitro antimicrobial susceptibility profile of these organisms, and from the need to start an effective combination therapy that does not interfere with other medications as soon as possible.

A decade surveillance study of Mycobacterium xenopi disease and antimicrobial susceptibility levels in a reference teaching hospital of northern Italy: HIV-associated versus non-HIV-associated infection

OBJECTIVE AND METHOD

The aim of our survey is to investigate the epidemiology and in vitro antimicrobial susceptibility levels of 35 consecutive Mycobacterium xenopi strains responsible for confirmed disease at a University Hospital from 1993 to 2002 and to identify eventual differences in the in vitro sensitivity profile between the 17 strains isolated from patients with HIV disease and the 18 isolates cultured from non-HIV-infected individuals.

RESULTS

The involvement of lower airways accounted for 88.6% of cases; but atypical pulmonary findings, including cavitation and a prominent inflammatory reaction, recently emerged in HIV-infected patients successfully treated with HAART, which raises the possible role of immune reconstitution syndrome in the clinical pathomorphism of this opportunistic disease. When compared with non-HIV-infected patients, patients with HIV disease had a lower mean age and a tendency to suffer from late relapses. The greatest overall in vitro sensitivity rate was registered for capreomycin and protionamide (100% of strains) followed by kanamicin (96.6%), whereas susceptibility rates for the first-line compounds such as ethambutol, isoniazid, and rifampicin were slightly lower (85.7% to 91.4%). No temporal variation in the susceptibility index was seen over the study decade. Non-HIV-infected patients experienced a higher frequency of M. xenopi isolates that proved to be resistant to at least one tested compound compared with HIV-associated episodes, despite the heavy and prolonged exposure of HIV-infected patients to broad spectrum antimicrobials, which included agents effective on atypical mycobacteria. Only one HIV-positive patient developed rifampicin resistance in his third disease recurrence.

CONCLUSION

A rapid diagnosis, a reliable differentiation between colonization and disease, and an optimal therapeutic choice for atypical mycobacterial disease (including M. xenopi one) are still serious challenges for clinicians and bacteriologists who treat immunocompromised patients, such as those with HIV disease. In the immunocompromised host, diagnostic difficulties posed by late identification and eventually concurrent opportunistic disorders add their negative effects to therapeutic problems due to the unpredictable in vitro susceptibility profile of atypical mycobacteria, such as M. xenopi.

Comparative evaluation of SensititreR YeastOne vs. the NCCLS M27A protocol and E-test for antifungal susceptibility testing of yeasts. Vergleichende Bewertung des SensititreR YeastOne vs. NCCLS M27A-Protokoll und E-test zur Empfindlichkeitsprufung von Hefen gegenuber Antimykotika

A recently developed microdilution method (Sensititre) YeastOne) may represent a valid alternative to the National Committee for Clinical Laboratory Standards (NCCLS) method for routine testing. The Medical Mycology Committee of the Associazione Microbiologi Clinici Italiani (AMCLI) decided to evaluate its reproducibility and reliability compared with the NCCLS M27A protocol and the E-test. Nineteen strains each of Candida albicans and Ca. parapsilosis, isolated from systemic infections, were tested against amphotericin B, flucytosine, ketoconazole, itraconazole, and fluconazole. All the participating laboratories tested the YeastOne panels, while the E-test and the NCCLS method were performed by two laboratories each. Interlaboratory reproducibility showed a good correlation (from 95% for amphotericin B to 92.5% for flucytosine). The agreement between NCCLS and YeastOne ranged from 95 (ketoconazole and itraconazole) to 100% (amphotericin B and flucytosine), whereas the agreement between E-test and YeastOne ranged from 72.5 (fluconazole) to 100% (amphotericin B and flucytosine). The Sensititre YeastOne panels appear to be an excellent alternative to both the E-test and the NCCLS protocol for antifungal susceptibility testing.

Proposal to elevate the genetic variant MAC-A, included in the Mycobacterium avium complex, to species rank as Mycobacterium chimaera sp. nov

The possibility that the strains included within the Mycobacterium avium complex (MAC), but not belonging either to M. avium or to Mycobacterium intracellulare, may be members of undescribed taxa, has already been questioned by several taxonomists. A very homogeneous cluster of 12 strains characterized by identical nucleotide sequences both in the 16S rDNA and in the 16S–23S internal transcribed spacer was investigated. Similar strains, previously reported in the literature, had been assigned either to the species M. intracellulare on the basis of the 16S rDNA similarity or to the group of MAC intermediates. However, several phenotypical and epidemiological characteristics seem to distinguish these strains from all other MAC organisms. The unique mycolic acid pattern obtained by HPLC is striking as it is characterized by two clusters of peaks, instead of the three presented by all other MAC organisms. All of the strains have been isolated from humans and all but one came from the respiratory tract of elderly people. The clinical significance of these strains, ascertained for seven patients, seems to suggest an unusually high virulence. The characteristics of all the strains reported in the literature, genotypically identical to the ones described here, seem to confirm our data, without reports of isolations from animals or the environment or, among humans, from AIDS patients. Therefore, an elevation of the MAC variant was proposed and characterized here, with the name Mycobacterium chimaera sp. nov.; this increases the number of species included in the M. avium complex. The type strain is FI-01069T (=CIP 107892T=DSM 44623T).

Using Apedin Vapor(R) in the control of Varroa mites and in honeybee feeding

A new natural formula, Apedin Vapor(R) (water, ethanol 19%, lactose and plant extracts: Echinacea angustifolia, Thuya occidentalis, Spiraea ulmaria and Oxalis acetosella) is considered a honeybee feed and an acaricide against Varroa mites. Colonies in apiaries in Northern Italy were sprayed with 50 ml of a 1:2 solution. After seven administrations at 19-28 day intervals (24 May-5 October 2002), acaricide efficacy reached 19.8%. In another trial, three doses at three-week intervals (the first on 18 May) were administered. Mite mortality was 54.1% and 22.6% in treated colonies and controls, respectively. A noticeable amount of parasites survived the treatment in both trials. The number of adult honeybees and brood cells in each colony were estimated according to the Liebefeld method (modified) before and after the treatment periods. No significant differences were recorded between treated and control groups in each trial. No external reaction to the treatment was detected. Small groups of bees were fed 60% sugar syrup, 60% sugar syrup and ethanol (19%), ethanol (19%), water, Apedin and a 1:2 solution of Apedin. The 60% syrup uptake was 81.5 mg/bee over a period of 28 h. The presence of ethanol seemed to considerably decrease the syrup palatability (the uptake was only 19.4 mg). 2.3 mg, 2.9 mg, 2.7 mg and 2.7 mg of water, ethanol, pure and diluted Apedin were removed, respectively and 84.6%, 80.0%, 71.4%, 74.5% of the bees were found dead or showed clear symptoms of starvation. Furthermore, respectively 0% and 37.5% of the bees in the groups fed plain syrup and syrup to which ethanol had added were dead or nonreactively lying on the bottom of the cages because of the insufficient feeding. The possible side effects of lactose as an Apedin Vapor(R) component are discussed.

Role of Mycobacterium xenopi disease in patients with HIV infection at the time of highly active antiretroviral therapy (HAART). Comparison with the pre-Haart period

BACKGROUND AND SETTING

A reliable and timely clinical, radiological, and bacteriological diagnosis, and an optimal treatment of non-tubercular mycobacteriosis (including Mycobacterium xenopi disease), remain an unanswered challenge for clinicians facing immunocompromised patients, including those with HIV infection.

OBJECTIVE

The aim of our survey is to report the frequency, and the epidemiological, immunological, microbiological, clinical, and therapeutic features of all confirmed HIV-associated M. xenopi disease observed from 1993-2002, with special attention paid to eventual differences that emerged after the introduction of potent antiretroviral therapy (highly active antiretroviral therapy, HAART), on the basis of an international literature update.

DESIGN AND RESULTS

Our series of 17 consecutive confirmed M. xenopi infections retrieved in 14 out of 3000 patients followed for HIV disease complications raises a broad series of clinical, diagnostic, therapeutic, and prophylactic concerns. The great majority of M. xenopi disease involved the lower respiratory tract, but atypical features including cavitation and prominent exudative features became apparent in patients successfully treated with HAART, pointing out the possible role of the so-called immune reconstitution syndrome in these episodes.

CONCLUSIONS

Diagnostic problems represented by late or missed identification due to slow culture and frequently concomitant opportunistic disorders, join therapeutic difficulties due to the unpredictable in vitro antimicrobial susceptibility profile of these organisms, selection of treatment and chemoprophylaxis according with clinical-radiological and microbiological suspicion, and concomitantly administered medications.

[Nosocomial sepsis due to Ochrobactrum anthropi in HIV positive patients: two case reports]

The first two case reports of nosocomial Ochrobactrum anthropi septicemia occurring in patients with HIV disease are presented, and discussed in light of recent evidence of non-fermenting gran-negative bacilli as emerging pathogens in hospitalized immunocompromised patients. Among patients with advanced HIV infection, O. anthropi septicemia may occur even when certain presumed risk factors (notably indwelling catheters and instrumentation) are lacking, while a low CD4+ lymphocyte count, neutropenia, and concurrent AIDS-related complications may act as predisposing conditions. Despite its low intrinsic pathogenicity, O. anthropi should be taken into consideration by both microbiologists and clinicians, due to its cumbersome identification procedures, its prevailing nosocomial occurrence, and its unpredictable antibiotic susceptibility pattern.

HIV disease and bacterial superinfections due to Xanthomonas spp.: a frequent association

Sixty-four episodes of Xanthomonas spp. infection were observed in 2.400 patients hospitalised for HIV disease (~2.7%) over an 8-year period: sepsi-bacteremia in 52 cases, lower respiratory tract infection in 6 cases, urinary tract infection in three patients, pharyngitis in two cases, and lymph node resented the fourth most common non-mycobacterial bacterial pathogens responsible for bacteremia in our HIV-infected patients: 52 cases out of 878 diagnosed (5.9%). The progression of HIV-related immunodeficiency, the occurrence of leukopenia-neutropenia, hospitalisation, previous antibiotic and/or corticosteroid treatment, and instrumentation, seemed to act as risk factors for the occurrence of Xanthomonas spp. infection. In three patients suffering from severe immunodeficiency and concurrent AIDS-related disorders, Xanthomonas spp. complication contributed to death, while a relapsing disease occurred in two cases only. Because of the poor antimicrobial susceptibility of these pathogens (also confirmed in our series), Xanthomonas spp. infection associated with advanced HIV disease and concurrent risk factors, may represent a potentially severe complication.

[Reduction of antibiotic resistance of Enterococcus faecalis in infections of the genitourinary tract]

Antimicrobial susceptibility levels of Enterococcus faecalis isolated from urine were followed up at our University Hospital during three years (1999-2001), in order to evaluate the trend of antibiotic resistance of this common community-acquired pathogen of the genito-urinary tract. One thousand and 249 consecutive strains were examined, and a surprisingly low resistance profile was detected. As a result, penicillin , ampicillin, nitrofurantoin and piperacillin may still represent first-line agents in our area when community-acquired urinary tract enterococcal infections is of concern, pending in vitro susceptibility studies.

[Methicillin-resistant Staphylococcus aureus: a three-year epidemiological and microbiological survey of high-risk patients]

In order to assess the frequency, and epidemiological and microbiological features, of respiratory and blood stream infection due to methicillin-resistant Staphylococcus aureus in high-risk patients, all S. aureus strains cultured from reliable clinical specimens (respiratory secretions obtained by tracheo-bronchial aspirate or bronchoalveolar lavage, or blood cultures), were prospectively evaluated over a three-year period, in six inpatient wards selected on the ground of an elevated frequency of severe and/or nosocomially-acquired infections, because of the prevalence of immunocompromised patients, organ transplant recipients, or need of intensive care. Repeatedly positive cultures obtained from a single patient within 30 days were considered as one isolate. Of 507 S. aureus strains responsible for pneumonia or sepsis in the selected wards, 317 (62.5%) proved methicillin-resistant, in absence of significant variations throughout the study period, and according to the specimen origin. Methicillin-resistant S. aureus strains prevailed over sensitive ones in all examined wards (from a 95% rate of the respiratory intensive care unit, to 55.9% of the pneumology department), save the neonatal and pediatric intensive care unit (41.4%). Most of methicillin-resistant S. aureus isolates were recovered from lower airways, compared with blood cultures (p<.0001). The majority of the 317 methicillin-resistant strains were found in the general intensive care unit (42.6%), followed by the pneumology department (18%), and the respiratory intensive care unit (16.4%). Among methicillin-resistant S. aureus strains, a broad variation of sensitivity to other antimicrobial agents was observed: from 3.3% of erythromycin, to 76.9% of chloramphenicol, and 79.7% of cotrimoxazole; glycopeptide antibiotics remained effective against all cultured strains. In our three-year survey of more than 500 episodes of documented staphylococcal infection involving high-risk patients, methicillin resistance was a very common feature, observed at a greater frequency than that reported in literature studies focusing on surgical, pneumological, or intensive care settings. A long-term microbiological monitoring of high-risk inpatient wards may allow a continued update of local antimicrobial susceptibility maps, and significantly add to both chemoprophylaxis and empiric treatment strategies of patients which are either immunocompromised or hospitalized for a long period.

Frequency, epidemiology, risk factors, clinical and bacteriological features of enterococcal disease in patients with HIV infection in a decade survey

In order to assess the frequency and clinical significance of Enterococcus spp. infection during HIV disease, the epidemiological features, risk factors, microbiological issues, and therapeutic perspectives of all the 148 consecutive episodes observed in the past decade were analyzed. The overall frequency of these complications (which involved the genito-urinary tract in over 75% of cases) regarded 5.3% of all admission for HIV disease, with a clear prevalence of Enterococcus faecalis as the causative agent (86.5% of episodes), and a proportionally elevated frequency of polymicrobial infection (45.9% of cases). Among the 148 cultured bacterial strains, a complete susceptibility to glycopeptide antibiotics was documented, together with favorable sensitivity levels against semisynthetic penicillins, followed by chloramphenicol, macrolides, and clindamycin. An advanced underlying HIV disease characterized by a concurrent, severe immunodeficiency, concomitant, prolonged neurological complications, hospitalization itself (with prevalence of nosocomial infection), recourse to invasive diagnostic and/or therapeutic procedures, and prior administration of broad spectrum antimicrobial agents, all seem to support HIV-associated enterococcal disease (mostly involving the genito-urinary tract). The adjunct of neutropenia, a very low CD4+ lymphocyte count, and severe AIDS-defining illnesses represented significant risk factors for hematogenous dissemination of this bacterial infection with potentially life-threatening consequences (16.1% of lethal cases among our septic patients).

Histoplasma capsulatum var. capsulatum occurring in an HIV-positive Ghanaian immigrant to Italy. Identification of H. capsulatum DNA by PCR from paraffin sample

Histoplasmosis, which is highly endemic in the United States, is rare in Europe, usually imported but sometimes autochthonous. In Africa, histoplasmosis capsulati coexists with "African histoplasmosis", a characteristic skin infection caused by H. capsulatum var. duboisii. Histoplamosis due to H. capsulatum is one of the 12 secondary infections listed in the surveillance definitions of AIDS. We report the case of a 36-year-old black man with acquired immunodeficiency syndrome (AIDS) who was living in Italy but originally came from Ghana. Histoplasmosis was disseminated with fever and cutaneous manifestations. The diagnosis was demonstrated morphologically based on the presence of yeast, observed by light microscopy, in skin lesions and by identification of H. capsulatum var. capsulatum DNA by nested PCR from a paraffin sample. No clinical reports of histoplamosis capsulati in Ghana have been published until now. The present case stresses the role of immigration of subjects from outside Europe who have been infected in their native country.

Enterobacter spp. infections complicating the course of HIV disease

Through a retrospective review of clinical and laboratory data of 2517 consecutive patients with HIV disease hospitalized since 1991, 13 patients were identified (0.52%), who suffered from a confirmed Enterobacter spp. infection (urinary tract disease in 7 cases, sepsis in 4 patients, and pneumonia in 2 cases). A severe immunodeficiency was recognized in all cases, as expressed by a mean CD4+ lymphocyte count <60 cells/microL, and frequently, a prior diagnosis of AIDS. Bloodstream infection proved linked to a lower mean CD4+ cell count, a more frequent occurrence of leukopenia-neutropenia, and nosocomial origin of the infecting pathogen. Hospital-acquired Enterobacter spp. disease was more frequent than community-acquired, and was significantly associated with leukopenia-neutropenia, and a diagnosis of AIDS. Antibiotic susceptibility assays showed a resistance rate to ampicillin and cephalothin involving >90% of tested strains, and a higher (but varied) sensitivity to other beta-lactams, aminoglycosides, fluoroquinolones, and cotrimoxazole. Adequate chemotherapy provided clinical and bacteriological success in all evaluated patients, in the absence of mortality or relapses. Only 34 episodes of HIV-associated Enterobacter spp. infection have been reported to date in 11 different literature studies. Our data point out that also Enterobacter spp. organisms may have an appreciable pathogenic potential in patients with HIV disease, especially in those with a low CD4+ lymphocyte count, leukopenia-neutropenia, who are hospitalized. Despite the unpredictable antibiotic susceptibility profile of these organisms, HIV-related Enterobacter spp. disease may be properly managed through rapid identification and timely and appropriate antimicrobial treatment.

An outbreak of Salmonella Hadar associated with roast rabbit in a restaurant

In August 1997, an outbreak of gastroenteritis from Salmonella Hadar phage type 2 occurred among customers of a restaurant in Rimini (Emilia-Romagna region, Italy). Twenty-nine people who had eaten food prepared in the restaurant on 2 or 3 August had symptoms of acute gastroenteritis. The infection was culture-confirmed in 24 cases and the stool specimens of four healthy people were positive for Salmonella Hadar. Twelve people had to be hospitalized and a 3-year old girl died. The case-control study identified roast rabbit as the likely vehicle of infection (OR: 6.00; CI 95%: 1.65-22.83). The microbiological investigation carried out on food taken from the restaurant confirmed high levels of Salmonella Hadar in a sample of roast rabbit. Since the rabbit was well cooked, the food contamination likely occurred after cooking. Poor hygienic conditions found in the restaurant, together with inappropriate food-handling practices and inadequate storage temperatures may have contributed to spread to other foods and the severity of the outbreak.

Performance assessment of new multiplex probe assay for identification of mycobacteria

A new DNA probe assay (INNO LiPA Mycobacteria; Innogenetics, Ghent, Belgium) for the simultaneous identification, by means of reverse hybridization and line-probe technology, of Mycobacterium tuberculosis complex, Mycobacterium kansasii, Mycobacterium xenopi, Mycobacterium gordonae, the species of the Mycobacterium avium complex (MAC), Mycobacterium scrofulaceum, and Mycobacterium chelonae was evaluated on a panel of 238 strains including, besides representatives of all the taxa identifiable by the system, a number of other mycobacteria, some of which are known to be problematic with the only other commercial DNA probe system (AccuProbe; Gen-Probe, San Diego, Calif.), and two nocardiae. The new kit, which includes a control probe reacting with the whole genus Mycobacterium, correctly identified 99.6% of the strains tested; the one discrepancy, which remained unresolved, concerned an isolate identified as MAC intermediate by INNO LiPA Mycobacteria and as Mycobacterium intracellulare by AccuProbe. In five cases, because of an imperfect checking of hybridization temperature, a very slight, nonspecific, line was visible which was no longer evident when the test was repeated. Two strains whose DNA failed amplification at the first attempt were regularly identified when the test was repeated. Interestingly, the novel kit dodged all the pitfalls presented by the strains giving anomalous reactions with AccuProbe. A unique feature of INNO LiPA Mycobacteria is its ability to recognize different subgroups within the species M. kansasii and M. chelonae, while the declared overlapping reactivity of probe 4 with some M. kansasii and Mycobacterium gastri organisms and of probe 9 with MAC, Mycobacterium haemophilum, and Mycobacterium malmoense, may furnish a useful aid for their identification. The turnaround time of the method is approximately 6 h, including a preliminary PCR amplification.

[Pathogenic role of Acinetobacter spp during HIV infection]

In order to assess the clinical role of bacterial complications due to Acinetobacter spp. during HIV disease, a retrospective survey of clinical and microbiological data of 2221 HIV-infected patients hospitalised during the past 10 years was carried out, evaluating all episodes of Acinetobacter spp. infection according to several epidemiological, clinical and therapeutic variables. Eleven patients of 2221 (0.5%) suffered from Acinetobacter spp. disease: sepsis in 5 cases, and urinary, respiratory tract disease and bacteremic pneumonia in three, two, and one patient respectively. A. calcoaceticus was responsible in 4 cases, A. lwoffii in three, and Acinetobacter spp. in the 4 remaining cases; 4 patients experienced a polymicrobial infection, and 7 had a prior diagnosis of full-blown AIDS. All patients had a severe HIV-related immunodeficiency (mean CD4+ lymphocyte count 118.2 +/- 45.3 cells/microl). Compared with other localizations, sepsis was related to a lower mean CD4+ cell count (p<.001), and a more frequent occurrence of leucopenia-neutropenia (p<.005). Disease episodes diagnosed after the first 72 hours of hospitalisation (deemed no- socomial in origin), proved more frequent than community-acquired ones (9 cases versus 2), affected predominantly patients with AIDS and neutropenia, and were frequent1y associated with bacteremia (p<.04) The use of broad spectrum antibiotics, corticosteroids and cotrimoxazole, was recognized during the month preceding the diagnosis of Acinetobacter spp. disease, in 6, 4, and 8 cases, respectively. One patient only had an indwelling intravascular catheter, while no recent history of surgery, intensive care, or other invasive procedures was found. At in vitro susceptibility studies, bacterial isolates showed complete resistance to ampicillin and cephalothin, and low sensitivity to second-generation cephalosporins, while a higher susceptibility rate was revealed towards ceftazidime, netilmicin, amikacin, and quinolones, followed by cotrimoxazole and piperacillin. A prompt and appropriate antimicrobial therapy (mostly carried out with cephalosporins and aminoglycosides), led all patients to a clinical and microbiological cure within 6-1.3 days, in the absence of mortality or relapses. As opportunist pathogens with a predominant nosocomial origin, Acinetobacter spp. organisms may be responsible for an appreciable morbidity in patients with HIV disease, especially when additional risk factors (immunodeficiency, underlying diseases, and hospitalisation) are present. Notwithstanding the high drug resistance profile of the majority of isolated organisms, a timely diagnosis and a treatment based on in vitro assays, contribute to avoid recurrences and potentially life-threatening complications.

Acinetobacter infections in patients with human immunodeficiency virus infection: microbiological and clinical epidemiology

BACKGROUND

We evaluated the role of complications caused by Acinetobacter spp. in the setting of HIV infection.

METHODS

Clinical records of 1,923 consecutive HIV-infected patients hospitalized in a 9-year period were retrospectively reviewed, in order to identify all cases of Acinetobacter spp. complications, and to assess their occurrence and outcome according to several epidemiological, clinical and laboratory parameters.

RESULTS

Ten patients out of 1,923 (0.52%) developed Acinetobacter spp. infections: sepsis in four cases, urinary tract infection in three, pneumonia in two and septicaemic pneumonia in the remaining patient. All patients were severely immunocompromised, as shown by a mean CD4+ lymphocyte count of 122 cells/microl and a frequent prior diagnosis of AIDS. As opposed to other infections, septicaemia was associated with a significantly lower CD4+ cell count and a more frequent occurrence of neutropenia. Hospital-acquired Acinetobacter spp. infections were significantly more frequent than community-acquired ones, and prevailingly involved patients with AIDS and leucopenia, being responsible for frequent blood dissemination. Antimicrobial, corticosteroid and cotrimoxazole treatment were frequently carried out during the month preceding disease onset. Antibiotic susceptibility studies proved the complete resistance of microbial isolates to ampicillin and cephalothin and poor sensitivity to second-generation cephalosporins and gentamicin, while greater susceptibility was shown to ceftazidime, netilmicin and amikacin, followed by piperacillin, cotrimoxazole and quinolones. Appropriate antimicrobial treatment led to clinical and microbiological cure in all cases, with no related mortality or relapses.

CONCLUSIONS

Since only 23 episodes of HIV-associated Acinetobacter spp. infections have been described to date in 11 different reports (nine cases of bacteraemia, eight of pneumonia, two of urinary tract involvement, one of intravenous access device infection, one of meningitis and two with unspecified localization), our series represents the largest one dealing with HIV-associated Acinetobacter spp. infections. According to our experience, Acinetobacter spp. may be responsible for appreciable morbidity among patients with HIV infection, above all when a low CD4+ cell count, neutropenia and hospitalization are present. Clinicians and microbiologists who work in the field of HIV infection should consider the potential pathogenic role of Acinetobacter spp. organisms even in the absence of some presumed risk factors, because of the relationship between these infections and immunodeficiency, hospitalization, other infectious complications, prior antibiotic and steroid treatment and extended antimicrobial resistance patterns.

Moraxella catarrhalis pneumonia during HIV disease

To assess the role of Moraxella catarrhalis complications in the setting of HIV disease, and to evaluate their occurrence and outcome according to several epidemiological, clinical, and laboratory parameters, the clinical records of 2123 consecutive HIV-infected patients hospitalized in a 9-year period were retrospectively reviewed, and 4 cases of community-acquired M. catarrhalis pneumonia were identified. Three adult patients had a diagnosis of AIDS and severe concurrent immunodeficiency (with a CD4+ lymphocyte count below 60 cells/microL), while the fourth case involved a child with vertical HIV disease. Leukopenia and neutropenia were never present, but no patient received a potent antiretroviral regimen at the time of disease onset. A concurrent respiratory infection by Streptococcus pneumoniae and Mycobacterium tuberculosis was recognized in 2 of 4 patients. Isolated M. catarrhalis strains were susceptible to all tested antimicrobial compounds (save ampicillin in 2 cases), and appropriate antimicrobial treatment led to clinical and microbiological cure in all described episodes. Only 8 cases of HIV-associated Moraxella spp. disease have been reported to date in seven different literature reports (6 cases of pneumonia, and 1 of septicemia). According to our experience, M. catarrhalis may be responsible for appreciable morbidity among patients with advanced HIV infection, especially when a low CD4+ cell count or coexisting respiratory disease are present. Clinicians and microbiologists who care for HIV-infected patients should carefully consider the potential pathogenic role of Moraxella spp. organisms.

Clinical and microbiological survey of Serratia marcescens infection during HIV disease

Clinical charts of 2,398 consecutive HIV-infected patients hospitalized over an 8-year period were reviewed retrospectively to identify all cases of Serratia infection and to evaluate the occurrence and outcome of these cases according to several epidemiological. clinical, and laboratory parameters. Seventeen of 2,398 (0.71%) patients developed Serratia marcescens infections: nine had septicaemia, six had pneumonia, one had a lymph node abscess, and one had cellulitis. All patients were severely immunocompromised, as evidenced by a mean CD4+ lymphocyte count of < 70 cells/microl and a frequent diagnosis of AIDS (13 patients). When compared with other disease localizations, septicaemia was related to a significantly lower CD4+ cell count and a more frequent occurrence of neutropaenia. Antibiotic, corticosteroid, or cotrimoxazole treatment was frequently carried out during the month preceding disease onset. Hospital-acquired Serratia spp. infection was more frequent than community-acquired infection and was significantly related to AIDS, neutropaenia, and sepsis. Antimicrobial sensitivity testing showed complete resistance to ampicillin and cephalothin but elevated susceptibility to ureidopenicillins, second- and third-generation cephalosporins, aminoglycosides, quinolones, and cotrimoxazole. An appropriate antimicrobial treatment attained clinical and microbiological cure in all cases, in absence of related mortality or relapses. Since only 13 episodes of HIV-associated Serratia spp. infection have been described until now in nine different reports (7 patients with pneumonia, 3 with sepsis, 1 with endophthalmitis, 1 with perifolliculitis, and 1 with cholecystitis), our series represents the largest one dealing with Serratia marcescens infection during HIV disease. Serratia marcescens may be responsible for appreciable morbidity among patients with HIV disease, especially when a low CD4 + cell count, neutropaenia, and hospitalization are present. The clinician and the microbiologist facing a severely immunocompromised HIV-infected patient with a suspected bacterial disease should consider the Serratia spp. organisms. In fact, a rapid diagnosis and an adequate and timely treatment can avoid disease relapses and mortality.

Histopathological evidence of North American blastomycosis in Italy: report of two cases

No clinical reports of blastomycosis in Italy have been published until now. We here report two cases of histologically diagnosed, unexpected cutaneous involvement in patients, aged 78 and 52 years, living in North Italy and never having been abroad. The histological differential diagnosis between blastomycosis and other fungal pathogens is discussed. Even in the absence of culture the present cases can confidently be considered as genuine examples of Blastomyces dermatitidis infection in Italy.

Pseudomonas spp. complications in patients with HIV disease: an eight-year clinical and microbiological survey

Two hundred and twenty-four episodes of Pseudomonas spp. complications that occurred in 179 consecutive patients with HIV infection were retrospectively reviewed. Pseudomonas spp. organisms were responsible for 11.6% of 1933 episodes of non-mycobacterial bacterial diseases (5.4% of 1072 episodes of sepsis), observed over an 8-year period; 20.7% of patients experienced disease relapses (45 episodes). These complications mostly involved lower airways (66 cases), urinary tract (53 episodes), and blood (34 cases), with Pseudomonas aeruginosa isolated in 161 episodes, and other Pseudomonas spp. in the remaining 63 cases. An advanced HIV disease was frequently present (as expressed by a prior diagnosis of AIDS, a low CD4+ lymphocyte count, and leukopenia-neutropenia). Indwelling intravascular and urinary catheters were often associated with bacteremia and urinary tract involvement, respectively. More than 60% of patients were given antibiotics and/or cotrimoxazole in the month preceding the onset of Pseudomonas spp. disease. Bacterial strains isolated from our HIV-infected patients showed a favorable sensitivity to piperacillin, ceftazidime, imipenem, amikacin, tobramycin, and ciprofloxacin. An adequate antimicrobial treatment led to clinical and microbiological cure in 73.2% of patients at the first episode, and in 22.3% more subjects after one or more relapses. A lethal outcome occurred in only eight patients of 179 (4.5%), suffering from a far advanced HIV disease; P. aeruginosa infection directly contributed to death in four cases (sepsis, and/or pneumonia). Nosocomial disease occurred in 46.4% of the 224 episodes, and was significantly related to a previous diagnosis of AIDS, concurrent neutropenia, the occurrence of sepsis or urinary tract infection, disease relapses, the involvement of non-aeruginosa Pseudomonas spp., and a lethal outcome, compared with community-acquired infection. Our experience (the largest reported to date) confirms that Pseudomonas spp. (including non-aeruginosa Pseudomonas spp. organisms) is responsible for remarkable morbidity and mortality among patients with HIV infection, and may pose relevant problems to clinicians and microbiologists involved in the care of HIV-infected patients.

Emerging gram-negative pathogens in the immunocompromised host: Agrobacterium radiobacter septicemia during HIV disease

Three out of 2,412 consecutive HIV-infected patients hospitalized since 1990, developed Agrobacterium radiobacter septicemia. All patients were severely immunocompromised, showing a prior diagnosis of AIDS, concurrent opportunistic infections, a mean CD4+ lymphocyte count below 100 cells/microL, and neutropenia. Nosocomial A. radiobacter sepsis occurred in two cases of three, and was related to a lower neutrophil and CD4+ cell count. Antibiotic and cotrimoxazole treatment were carried out during the month preceding disease onset by two and three patients, respectively. Antimicrobial susceptibility assays showed resistance to ureidopenicillins and aztreonam, and complete sensitivity to carbapenems, amikacin, and ciprofloxacin. A therapeutic regimen including amikacin plus ceftriaxone or ceftazidime obtained clinical and microbiological cure in all cases, in the absence of related mortality or relapses. Only two episodes of HIV-associated A. radiobacter complications have been described to date: one case of sepsis and one patient with pneumonia. Despite their low frequency, gram-negative non-fermenting bacilli should be considered in HIV-infected patients with a suspected bacterial complication, because of their cumbersome identification procedures, and their unpredictable antibiotic susceptibility, with elevated resistance to many compounds expected to be effective against gram-negative organisms. A. radiobacter may play a pathogenic role in patients with advanced HIV disease, even when some commonly recognized risk factors are lacking (in-dwelling catheters and instrumentation), while a very low CD4+ lymphocyte count, leukopenia-neutropenia, hospitalization, and concurrent AIDS-related infectious complications, may act as predisposing factors.

Flavobacterium spp. organisms as opportunistic bacterial pathogens during advanced HIV disease

OBJECTIVE

To assess the role of Flavobacterium spp. infection in patients with HIV disease.

METHODS

Clinical charts of 2412 consecutive HIV-infected patients hospitalized in a 8-year period were retrospectively reviewed, to identify all cases of Flavobacterium spp. infections, and to evaluate their occurrence and outcome according to several epidemiological, clinical, and laboratory parameters.

RESULTS

Six patients out of 2412 (0.25%), developed Flavobacterium spp. complications: septicaemia in five cases, and pneumonia in the remaining patient, with F. meningosepticum and F. odoratum isolated in two cases and one case, respectively, and unnamed Flavobacterium spp. organisms in the remaining three cases. Flavobacterium spp. organisms were responsible for six out of 1939 overall episodes of non-mycobacterial bacterial diseases observed in our patient group (0.31%). All patients were severely immunocompromised, showing a prior diagnosis of AIDS, a mean CD4+ lymphocyte count of 64.2 (range 12-187) cells/microl, and a mean neutrophil count of 1.143 (range 700-1600) cells (range 700-1600) cells/microl. Antibiotic, corticosteriod, or cotrimoxazole treatment was carried out during the month preceding disease onset by three, two and five patients, respectively. Community-acquired and nosocomial Flavobacterium spp. disease were equally frequent, but the latter occurred with a significantly lower mean neutrophil and CD4+ cell count. Antimicrobial susceptibility assays showed complete sensitivity to ciprofloxacin, and variable resistance to ureidopenicillins, ceftazidime, imipenem, aztreonam, and aminoglycosides. An appropriate antimicrobial regimen obtained clinical and microbiological cure in all cases, in absence of related mortality or relapses.

CONCLUSIONS

Since only one episode of HIV-associated F. (Sphingobacterium) multivorum complication has been described to date, our series represents the largest one dealing with Flavobacterium spp. infection in the setting of HIV disease. Our experience suggests that Flavobacterium spp. organisms may play a pathogenic role in patients with advanced HIV disease, even when some commonly recognized risk factors are lacking (i.e. indwelling catheters, instrumentation, IV drug abuse), while a very low CD4+ lymphocyte count, leukopaenia-neutropaenia, and concurrent AIDS-related infectious complications may act as important predisposing factors. In view of the infrequent occurrence of these infections, early suspicion is essential for both clinicians and microbiologists facing immunocompromised patients at risk for invasive bacterial complications. Flavobacterium spp. organisms should be taken into consideration as nosocomial- or community-acquired opportunistic pathogens, due to their relationship with advanced immunodeficiency and their elevated resistance to many antimicrobial agents commonly used against Gram-negative bacterial pathogens.

Fatal Campylobacter jejuni bacteraemia in patients with AIDS

Two fatal cases of Campylobacter jejuni septicaemia in patients with AIDS were characterised by severe HIV-related immunodeficiency, negative stool cultures and presentation during hospitalisation, developing a clinical picture of fulminant septic shock despite therapy with appropriate antibiotics. Campylobacter spp. are important opportunist pathogens in HIV disease and may cause a septicaemic illness in the absence of enteric disease.

AIDS-related visceral aspergillosis: an underdiagnosed disease during life?

Five out of nine consecutive patients with HIV-related visceral aspergillosis observed by us since 1984 were diagnosed only at necropsy examination. The histopathological features of these five patients [two with isolated pneumonia, one with central nervous system (CNS) involvement, one with brain abscess and respiratory disease and one with pulmonary, pleural and kidney infection] have been evaluated according to epidemiological, clinical and radiological features. On the basis of our experience, life-threatening aspergillosis, which is often misdiagnosed or missed in the setting of HIV infection and AIDS, should be suspected in patients with far-advanced underlying disease and unexplained signs and symptoms, even in the absence of some presumed risk factors (i.e. neutropenia and prior steroid treatment). Plain chest radiography and bronchoscopy with broncholaveolar lavage may fail to reveal respiratory disease, CNS aspergillosis is not necessarily associated with suggestive neuroradiological features and disseminated disease may present with multiorgan failure. The unfavorable outcome of this emerging AIDS complication can be improved only by earlier diagnosis based on invasive techniques and appropriate and timely treatment.

Xanthomonas maltophilia: an emerging pathogen in patients with HIV disease

Fifty-four episodes of Xanthomonas maltophilia infection were observed in 52 HIV-infected patients out of 2062 assessed (2.52%) over a 6-year period: sepsis/bacteraemia in 44 cases, lower airways infection in 5 cases, urinary tract infection and pharyngitis in 2 cases each, and lymph node involvement in one patient. X. maltophilia represented the fourth most common non-mycobacterial bacterial pathogen responsible for bacteraemia in HIV-infected patients: 44 cases out of 721 diagnosed (6.1%). When compared with non-typhoid Salmonella spp. bacteraemia, an increased risk to develop X. maltophilia disseminated infection was seen according to the progression of HIV-related immunodeficiency, the occurrence of leukopenia-neutropenia, central venous catheterization, previous antibiotic and/or corticosteroid treatment, and hospitalization. In 3 patients suffering from concurrent AIDS-related disorders, X. maltophilia infection contributed to death, while a recurrence occurred in 2 cases only. Due to the poor antimicrobial susceptibility of this pathogen (also confirmed in our series), X. maltophilia bacteraemia associated with advanced HIV infection and concurrent risk factors, may represent a potentially severe disease.