Morena Ferri

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.

Fiavobacteriurrt 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.

Bacteremia and respiratory involvement byAlcaligenes xylosoxidans in patients infected with the human immunodeficiency virus

Seven cases ofAlcaligenes xylosoxidans bacteremia and/or respiratory disease in patients infected with the human immunodeficiency virus (HIV) are described. Reported only thrice previously in this setting, these bacterial complications occurred during different phases of HIV infection and were associated with leukopenia-neutropenia in four patients and a central vascular catheter in two. Although the majority of cases were diagnosed after day 3 of hospitalization, a distinct source of infection was never identified. In four patients with advanced underlying disease, a polymicrobial infection was present. In vitro resistance to aminoglycosides, first-generation cephalosporins, and aztreonam was identified, but treatment with fluoroquinolones, piperacillin, or an aminoglycoside in combination with either ceftazidime or pefloxacin was successful in all cases. The relevance ofAlcaligenes xylosoxidans and related species of gramnegative non-glucose fermenting bacilli as opportunistic pathogens in the immunocompromised host and in the setting of HIV infection is briefly reviewed.

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.

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.

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

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.

Clinical and Microbiological Survey of Serratia marcescens Infection During HIV Disease

Abstract Clinical charts of 2398 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 2398 (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/μl 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.

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.

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

Abstract 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.

Streptococcus bovis bacteremia in patients infected with the human immunodeficiency virus: case reports and literature review.

Streptococcus bovis is classified among the group D streptococci on the basis of its reaction with specific antiserum and because it exhibits several properties in common with group D organisms. It is included among nonenterococcal group D streptococci, since these organisms are unable to grow in salt solution and show a distinct susceptibility to penicillin [1]. Streptococcus bovis (the only lactose-fermenting species among nonenterococcal group D streptococci) is usually nonhemolytic and cannot hydrolyze hippurate. It may colonize the enteric tract of animals and humans: stool carriage has been shown in over 10% of immunocompetent subjects and has been demonstrated more frequently in patients with gastrointestinal disorders, especially in those with malignant or premalignant conditions [1–4].