Epidemiological and clinical features of prosthetic joint infections caused by gram-negative bacteria.

OBJECTIVE: To review the clinical literature focusing on epidemiology, clinical presentation and outcomes of prosthetic joint infections (PJIs) due to gram-negative bacteria (GNB) and to report the experience of a multicentric cohort. PATIENTS AND METHODS: A retrospective, observational, cohort study was performed in three Italian hospitals. All consecutive PJIs caused by GNB over a 12-year period (from May 2007 to March 2018) were enrolled. Epidemiological, clinical, microbiological and therapeutic features were described. Factors related to treatment failure (defined as the occurrence of death, amputation or starting long-term antimicrobial suppression therapy) were analysed with a Cox regression model. RESULTS: A total of 82 PJIs due to GNB (42.7% men; median age 73 years) were studied. The implants included 65 (79.3%) hip, 16 (19.5%) knee and one (1.2%) shoulder. An early PJI was diagnosed in 16.2% of patients, a delayed PJI in 29.4% and a late PJI in 54.4%. The most common isolated organisms were Escherichia coli (21.7%) and Pseudomonas spp. (20.9%). 13.4% of the isolates were carbapenem-resistant bacteria (CRB). In 53.8% of cases a two-stage exchange arthroplasty was performed and in 32.5% a Girdlestone excision arthroplasty. The average therapeutic failure occurred in 17.7% of cases. The therapeutic failure rate of the two-stage was 10%. PJI due to CRB was identified as a potential risk factor for failure (aHR 4.90; IC 95%, 0.96-25.08; p=0.05). The therapeutic failure rate in the CRB group was 50%. CONCLUSIONS: The treatment with the two-stage procedure for PJIs caused by GNB seems to be associated with a low rate of failure, while PJI due to CRB seems to be related to the worst outcome.

[Chronic osteomyelitis due to Pseudomonas aeruginosa: treatment with elastomeric infusor in an outpatient setting]. / Osteomielite cronica daPseudomonas aeruginosa:trattamento antibioticodomiciliare con impiegodi elastomero.

Chronic bacterial osteomyelitis requires long-term antibiotic treatment (at least 6-8 weeks). After in-hospital management, patients are usually discharged and treated in outpatient settings. However, when the aetiology is represented by Gram-negative microorganisms, outpatient treatment could be difficult. Beta-lactam administration by means of an elastomeric infusor may represent an attractive approach. We report two cases of osteomyelitis due to Pseudomonas aeruginosa successfully treated with continuous ceftazidime administration via an elastomeric infusor in outpatient settings. In both cases the patients were free from clinical and laboratory signs of osteomyelitis at the end of treatment and after 12 months follow-up.

Etiology of prosthetic joint infections in a tertiary care centre in Italy.

Prosthetic joint infections (PJIs) represent a severe complication in orthopaedics. Coagulase-negative staphylococci (CoNS) and Staphylococcus aureus represent the most frequent cause, but Gram-negatives have also been reported. With a view to describing the aetiology of PJIs diagnosed from January 2005 to September 2007 at S. Corona Hospital in Pietra Ligure, Italy, we conducted retrospective analysis of pathogens isolated from PJIs by means of surgical specimens, needle aspirates or swabs of fistula (3 samples). During the study period 228 PJIs were described and 141 (62%) were microbiologically documented and evaluated. Early and delayed infections represented 45% of episodes, while late infections were observed in 55%. The aetiology was mono-microbial in 84% of cases, and polymicrobial in 16%. CoNS and S. aureus were the most frequently isolated pathogens. In early and delayed infections methicillin resistant CoNS were 30% and 24%, respectively, while in late infections they were 17%. Methicillin-resistant S. aureus was isolated in 13% of early, 22% of delayed and 15% of late infections. Gram-negatives were described in 16% of episodes without differences being found in the three groups. In our report staphylococci represented the most frequent cause of PJIs. Methicillin-resistant strains were more frequently isolated in early and delayed infections, but their frequency in late episodes was not negligible. Polymicrobial infections and Gram-negative infections were also frequent.

[Bacterial infections in HIV patients]. / Infezioni batteriche in pazienti con malattia da HIV.

AIM OF THE STUDY AND METHODS: Retrospective analysis of bacterial infections occurring in 400 admissions of HIV-positive patients in the Infectious Diseases Unit of the Azienda Ospedale Santa Corona, Pietra Ligure (SV), from January 1994 to September 1996. RESULTS: 56 episodes were documented (14% of admissions): 24 (43%) hospital acquired (11 sepsis, 5 pneumonias, 6 urinary-tract infections, 1 infection of a prosthetic device) and 32 (57%) community-acquired (9 sepsis, 13 pneumonias [6 with bacteremia] 9 urinary-tract infections, 1 endocarditis). At time of diagnosis mean absolute CD4-lymphocyte count was 106/cmm (95% Cl 62-150) and mean neutrophil count was 4.690/cmm (95% Cl 3.466-5.914); 11 patients had a central venous catheter, 9 a vesical catheter and 7 severe skin lesions. Methicillin-resistant S. aureus (11/24, 46%) and Pseudomonas (8/24, 33%) were the most frequently isolated pathogens in hospital infections, while the majority of community acquired episodes were due to S. pneumoniae (10/32, 31%). In six episodes (11%) the patient died because of the bacterial infection. CONCLUSIONS: Bacterial infections are quite frequent in this cohort of HIV-infected patients. Methicillin-resistant S. aureus and Pseudomonas represented the major cause of hospital acquired infections, while S. pneumoniae represented the major cause of community acquired episodes.

[Toxic shock syndrome due to Streptococcus pyogenes: a case report]. / Sindrome da shock tossico da Streptococco pyogenes: descrizione di un caso clinico e revisione della letteratura.

An increasing number of severe invasive Group A streptococcal infections have recently been reported. A new syndrome similar to the staphylococcal toxic shock syndrome, defined "streptococcal toxic shock-like syndrome" is also described. We report a case of streptococcal toxic shock-like syndrome with atypical clinical onset. A 67 years old man was admitted on the emergency department because of pain in the scapular area without fever. The patient developed irreversible shock and died after 36 hours. Diagnosis was made with autopsy. We stress the possibility of infectious cause in presence of severe multi organ failure with rapid clinical exacerbation.

Prophylaxis of streptococcal bacteraemia with oral penicillin V in children undergoing bone marrow transplantation.

The work described aimed to evaluate the incidence of streptococcal bacteraemia in children undergoing bone marrow transplantation and receiving prophylaxis with penicillin V. From January 1991 to December 1993 oral penicillin V was administered as prophylaxis for streptococcal bacteraemia to patients undergoing bone marrow transplantation at G. Gaslini Children's Hospital, Genoa, Italy. The data were compared with those from a similar population receiving bone marrow transplantation from September 1984 to July 1990 and not receiving this kind of prophylaxis. Streptococcal bacteraemia was diagnosed in 7/17 (41%) episodes of bacteraemia observed in the period January 1991 to December 1993, while it accounted for 71% of all bacteraemias in the period from September 1984 to July 1990 and was especially frequent from January 1988 to July 1990, comprising 13/15 (87%) of observed bacteremias. The decrease of this complication observed after the beginning of the prophylaxis programme was statistically significant. Oral penicillin V is effective as prophylaxis of streptococcal bacteraemias in children receiving bone marrow transplantation in a centre with a high incidence of this complication.

T cell blastogenic responses to Toxoplasma gondii trophozoites among HIV-infected patients.

OBJECTIVE: To evaluate the cell-mediated immune response to Toxoplasma gondii (T. gondii) among HIV-infected patients. METHODS: Forty HIV-infected patients were studied. Of them, 35 had antibodies to T. gondii and 5 had not. Nine of 35 patients with detectable serum Toxoplasma antibodies were classified as group A1 (CDC 1993), 10 as group B2, 6 as group B3, and 10 as group C3. Peripheral blood mononuclear cells (PBMCs) were obtained by Ficoll-Hypaque gradient centrifugation. Living Toxoplasma gondii trophozoites, herpes simplex virus (HSV), tetanus toxoid, and phytohemoagglutinin (PHA) were used in standard proliferation assays. Toxoplasma-responding blasts were expanded and assayed for antigen specificity and HLA restriction by proliferation assays. T cell subsets were analyzed using two-color flow cytometry. RESULTS: Among patients with detectable Toxoplasma serum antibodies, significant PBMC proliferation in response to T. gondii trophozoites was observed in those classified in group A1 or B2 but not in those in groups B3 and C3. Toxoplasma-induced blasts from five of six patients after 7 days of culture and from five patients after 15 days of culture proliferated in response to T. gondii in the presence of either autologous or allogeneic PBMCs as antigen-presenting cells (APCs) and/or also proliferated in response to HSV. The surface markers of T. gondii-induced blasts showed a variable percentage of CD4 and CD8 activated cells. CONCLUSIONS: T cell proliferative response to living trophozoites of T. gondii is lost only in patients with severe depletion of CD4 cells. PBMC proliferation was observed only in patients with previous T. gondii infection, but the T cell blasts generated showed a strong alloreactivity (proliferating in response to allogeneic irradiated PBMCs) and were apparently not antigen specific (proliferating also in response to HSV).

[Sepsis in children with malignant neoplasia, equipped with a Broviac-type venous catheter]. / Sepsi in bambini affetti da neoplasia maligna portatori di catetere venoso centrale tipo Broviac.

Indwelling central venous catheters obviate many problems in the care of children with malignancies, but they also are a well-known source of infection. We are reviewed the history of 584 Broviac catheters inserted from January 1984 to December 1991, in 475 children with cancer in order to assess the etiology of bacteremias, their association with neutropenia and their relationship with the presence of the catheters. The overall duration-time of the catheters, employed for blood tests, drug and blood infusions and parenteral nutrition, was 1-835 days (median 263, mean 186). Total catheter courses was 108.678 days. In this period 226 episodes of sepsis were observed in 180 patients: 157 in neutropenic patients and 69 in non neutropenic. Catheter related bacteremias were diagnosed in 65/226 episodes (29%): 23 (35%) were observed in neutropenic patients and 42 (65%) in non neutropenic (P < 0.005). Gram-positive pathogens were isolated in 28/65 (43%) episodes, Gram-negatives in 15/65 (23%), fungi in 9/65 (14%), and the remaining 13 (20%) were polymicrobial. In the last years we observed an increase of catheter related bacteremias due to Gram-negative rods no change was observed in pathogens causing catheters unrelated bacteremias. The high incidence of catheters related bacteremias in non neutropenic, non hospitalized patients, stress on the home-care of the catheters; a high level of suspicion of Gram-negative infections should be maintained in cancer patients with an indwelling central venous catheters.

Changing pattern of pathogens causing broviac catheter-related bacteraemias in children with cancer.

The incidence of pathogens causing catheter-related bacteraemias in children undergoing antineoplastic chemotherapy with or without bone marrow transplantation at G. Gaslini Children's Hospital, Genoa, Italy, was analysed by comparing data from a retrospective study (1985-1988) with that obtained from a prospective one (1989-1992). In both periods catheter-related bacteraemias one (1989-1992). In both periods catheter-related bacteraemias were more frequent in non-neutropenic than in neutropenic patients. Among catheter-unrelated bacteraemias the pattern of infecting pathogens remained unchanged between the study periods, with Gram-positive bacteria remaining the predominant pathogens. Conversely, among catheter-related bacteraemias, the incidence of Gram-negative bacilli increased significantly from 3 to 38%, and that of Gram-positive bacteria fell from 63 to 32% (P = 0.001, chi 2 test for heterogeneity.

Herpes simplex virus and oral mucositis in children with cancer.

The relationship between herpes simplex virus (HSV) and oral mucositis was investigated in children undergoing antineoplastic chemotherapy. HSV culture was performed in 20 children with stomatitis developing after antineoplastic chemotherapy. Viral isolates were typed and susceptibility to acyclovir was investigated. The virus was isolated from oral lesions in 10 of 20 children with severe oral mucositis. Viral reactivation was the most likely explanation in most cases, since HSV was isolated in 9 of 13 seropositive patients (and in 1 patient with unknown anti-HSV serology), but in no seronegative patient. HSV type 1 was isolated more frequently than HSV type 2 (8 versus 2). Acyclovir showed standard in vitro activity against all isolates. Our results suggest that oral mucositis in children receiving antineoplastic treatment is probably multifactorial in origin and that HSV can be an important cofactor, especially in children who are seropositive for HSV. In our Centre, acyclovir remains active in vitro against this opportunistic pathogen and could be employed in prophylaxis and therapy.

Mycobacterial diseases and HIV infection.

OBJECTIVES: Evaluation of the incidence of mycobacterial diseases in patients infected with human immunodeficiency virus (HIV) and analysis of survival after diagnosis of mycobacteriosis. METHODS: Retrospective analysis of clinical and laboratory data of HIV-infected patients admitted in our hospital from January 1st, 1985 to March 31st, 1992. RESULTS: We observed 82 infections in 81 patients with an increase in the annual percentage from 2.2% to 6.4%. M. tuberculosis more than atypical Mycobacteria was found in patients with pulmonary infection (p = 0.03). Forty patients had a previous diagnosis of acquired immunodeficiency syndrome (AIDS) and 24 evolved in AIDS because of mycobacterial infection. We observed infection due to M. tuberculosis in patients with advanced HIV-infection (20/27 patients with tuberculosis had CD4+ cell count < 200/cm3). Mean survival after diagnosis and treatment was 329 days with better survival in patients with CD4+ cell count > 200/cm3 (p = 0.03). We did not find a statistically significant difference in survival between patients with tuberculosis and other mycobacteriosis. CONCLUSIONS: Mycobacterial infections are increasing in HIV-infected patients, and tuberculosis is observed also in patients with advanced immunodeficiency. Survival is influenced by the severity of immunodeficiency more than by the mycobacterial species.

Cutaneous cryptococcosis resembling molluscum contagiosum in a homosexual man with AIDS. Report of a case and review of the literature.

A 43-year-old homosexual man with the Acquired Immunodeficiency Syndrome (AIDS) developed cutaneous molluscum contagiosum-like lesions on face, ears, neck, hands and feet. He was admitted to our unit with fever, malaise and headache. Cytologic examination of skin brushing revealed numerous encapsulated budding yeasts, identified as Cryptococcus neoformans. Such a finding calls for a cytologic examination of skin lesions in patient with AIDS who present with fever and headache, in order to rule out a potentially life-threatening fungal infection.