Nosocomial infections in the rehabilitation department.

AIM: The patients of a Rehabilitation Department are at high risk of nosocomial infections because they generally have a long term hospitalisation and more and more frequently immune-compromised subjects, like old patients or with chronic illness, are admitted to rehabilitation programs. However, to evaluate the real infectious risk of a Rehabilitation Unit, it is important to consider also that a high number of patients are transferred from other hospitals after a specific therapy of the acute phase of their medical or surgical pathology and so many nosocomial microrganisms previously acquired may spread to a Rehabilitation Unit. METHODS: From January to December 2003 we have performed a screening of the bacteruria among the patients at admittance to the Rehabilitation Unit of S. Orsola Fatebenefratelli Hospital of Brescia (Italy). RESULTS: A significant bacteruria (>100000 cfu/mL) in 28.9% of 114 patients coming from home and in 41.9% of 179 patients transferred from other hospitals without antibacterial treatment has been documented. CONCLUSIONS: These findings confirm the presence of an high number of patients colonized or infected by nosocomial bacteria previously acquired in hospital and underline the need, in addition to specific skill, of wide infectious knowledge among the medical staff of a Rehabilitation Unit. A specific approach to the infectious problem in the Rehabilitation Department in order to reduce the risk of nosocomial infections may be suggested.

Isolation of HTLV-1 from an aggressive form of ATL in a Romanian patient not at risk of infection and with seronegative family members.

We present the clinical, virological and haematochemical data of a 22 year old patient from Romania with Adult T Cell Leukaemia (ATL). Viral isolation in peripheral mononuclear blood cells (PMBC), detection of DNA sequences of HTLV-1 by Polymerase Chain Reaction (PCR) and of antibodies by Elisa and Western blot were performed. The patient does not belong to any risk group and additionally all members of her family are seronegative for HTLV-1, the aetiological agent of ATL. The role of viral infection remains open.

Diagnosis of bronchopulmonary infections by quantification of microflora.

The quantification of bacteria and fungi in sputum or bronchoaspirate is of clinical value for the diagnosis of respiratory tract infections. We have developed an easy method to count the micro-organisms in patients with respiratory tract infections. This consists of the quantification of micro-organisms by subsequent streakings of a calibrated loop on agar. The correlation between microbiological quantitative data and the clinical status of patients with lower respiratory tract infections is discussed. The data seem to indicate that certain bacteria present in sputum or bronchoaspirate above a certain concentration may be responsible for lower respiratory tract infections. In patients with immunological disorders or chronic pathologies even lower concentrations of micro-organisms in bronchial secretions probably are enough to cause infections. The advantage of this counting method of the microbic species from the respiratory tract consists of their quantification: thus we can attribute an etiological role to a high concentration of the germs, while micro-organisms at low concentrations are probably contaminants. By this method isolated colonies are obtained after 12-18 hours. The bacterial quantification, by respiratory samples examination of the same patient in the following days, allows us to evaluate the efficacy of antibacterial therapy, producing a reduction of bacterial concentration.

In vitro antibacterial activity of the new quinolone Bay y3118 against clinical isolates.

The in vitro antibacterial activity of the new fluoroquinolone Bay y3118 against 609 clinical isolates was evaluated. Bay y3118 exhibited activity against a broad spectrum of organisms, including Gram-negative bacilli, Gram-positive cocci, mycobacteria. The activity of Bay y3118 was often superior to that of other quinolones. Against Gram-negative bacilli its activity was similar to that of ceftriaxone, cefotaxime, ceftazidime and imipenem except for Serratia marcescens, Klebsiella pneumoniae, Enterobacter spp. and Xanthomonas maltophilia, where its activity was superior. Gentamicin and piperacillin sometimes were less active. Bay y3118 was active against a large number of Gram-positive cocci. The fluoroquinolones tested were active against all the strains of Mycobacterium tuberculosis, but only Bay y3118 was effective against Mycobacterium avium.

Persistence of human T cell lymphotropic virus type 1 (HTLV-1) sequences in peripheral blood mononuclear cells from patients with mycosis fungoides.

Mycosis fungoides (MF) is a rare form of cutaneous T cell lymphoma suspected of having a viral etiology. As in adult T cell leukemia, the virus involved may be human T lymphotropic virus type 1 (HTLV-1). We cultured the peripheral blood mononuclear cells (PBMC) of 29 patients with MF HTLV-1 seronegative by enzyme-linked immunosorbent assay and Western blot. The presence of reverse transcriptase (RT) and p24 antigen was investigated in the concentrate supernatant of the culture. The DNA of all studied patients was submitted to polymerase chain reaction and Southern blot analysis using primers and probes recognizing the tax region of HTLV-1/2 and the pol region of HTLV-1. 10 of 29 patients were found positive to HTLV-1, whereas they were always negative to RT and p24. The same results were confirmed in double blind after 6 mo. Our findings suggest HTLV-1 may be involved in the etiology of MF, at least in certain cases.

Rapid methods for microbial diagnosis of mycobacterial infections.

The Authors describe their experience in rapid diagnosis of mycobacterial infections using a combination of a radiometric blood culture (Bactec 13 A) and a nucleic acid hybridization system (Gen probe, Accuprobe) to detect and identify Mycobacteria. They found out that a high number of septicaemias in HIV positive patients are due to Mycobacterium avium, while in HIV negative subjects Mycobacterium tuberculosis is the most frequent mycobacterium.

HTLV-1 sequences in lymphocytes of a patient with non-tropical spastic tetraparesis and her asymptomatic husband.

We describe a 65-year-old woman born and living in Northern Italy affected by non tropical spastic tetraparesis and her asymptomatic husband presenting HTLV-1 sequences in their lymphocytes detected by polymerase chain reaction (PCR). We discuss the significance of the case and the mechanism involved in HTLV-1 infection and the relationship with neurological disorders, stressing that this case is the first reported in Italy.

Antibacterial activity of the new carbapenem meropenem (SM-7338) against clinical isolates.

The in vitro antibacterial activity of the new carbapenem antibiotic meropenem (SM-7338) against 567 clinical isolates was evaluated. SM-7338 exhibited activity against a broad spectrum of organisms, including aerobes and anaerobes, and was superior to the other beta-lactam drugs tested (piperacillin, cefotaxime, ceftazidime, ceftriaxone, cefoxitin). SM-7338 was more active than imipenem, gentamicin and amikacin against Enterobacter cloacae and Pseudomonas aeruginosa. SM-7338 was less potent than imipenem against staphylococci and enterococci, but the activity of the two antibiotics against anaerobes was similar. SM-7338 and imipenem showed a high bactericidal activity at a concentration of 2-4 x MIC.

In-vitro activity of meropenem against clinical isolates in a multicentre study in Italy.

A multicentre in-vitro study was undertaken to evaluate the susceptibility of bacterial pathogens isolated in different Italian hospitals to meropenem. A total of 1399 aerobic and 452 anaerobic strains was analysed. Comparative agents were imipenem, cefotaxime, ceftazidime, ceftriaxone, piperacillin, ciprofloxacin, gentamicin, amikacin, plus vancomycin when appropriate. The MIC ranges (mg/l) of meropenem were: 0.015-2 for Klebsiella spp., Proteus spp., Morganella morganii and Providencia spp.; less than 0.008-1 for Escherichia coli; 0.016-32 for Serratia spp.; 0.03-2 for Enterobacter spp. and Citrobacter spp.; 0.03- greater than 128 for Acinetobacter anitratus; 0.03-32 for Pseudomonas spp.; less than 0.008-0.5 for Haemophilus spp. and Neisseria spp.; 0.015-64 for Staphylococcus spp.; 0.06- greater than 128 for Enterococcus spp.; less than 0.008-0.25 for Streptococcus spp.; 0.016-8 for Fusobacterium spp.; 0.03-8 for Bacteroides spp.; less than 0.06-0.5 for anaerobic Gram-positive cocci; 0.08-2 for Clostridium spp. Meropenem exhibited superior antibacterial activity against the aerobic and anaerobic strains tested when compared to the other beta-lactam drugs. The new carbapenem was as active as ciprofloxacin and more active than imipenem and the aminoglycosides against Enterobacteriaceae and Ps. aeruginosa. It was also more active than ciprofloxacin against most strains of Gram-positive cocci. Meropenem was slightly less potent than imipenem against staphylococci and enterococci, with the exception of oxacillin-susceptible Staph. aureus against which meropenem and imipenem exhibited similar antibacterial activity.

HTLV-1 seroprevalence in AIDS patients and in HIV-1 seropositive and seronegative subjects at risk for AIDS in northern Italy.

Sera of 1023 subjects belonging to categories at risk for AIDS, positive for HIV-1, were tested for antibodies to human T-cell leukemia virus (HTLV-1) by ELISA, Western blotting, and radioimmunoprecipitation (RIP) assay. Sera of these subjects were positive for antibodies to HTLV-1 in a percentage of 18.54%. Nine out of 18 sera from patients with AIDS had antibodies to HTLV-1 (50%). Sera of 207 intravenous drug abusers and 64 homosexual males, seronegative for HIV-1, were tested for antibodies to HTLV-1 and 6.7% of intravenous drug abusers and 7.8% of homosexual males were found to be HTLV-1 antibody positive, showing that HTLV-1 infection occurred independently of HIV-1 and HIV-2 infections. In fact the same HIV-1 seronegative patients were also tested for the presence of antibodies to HIV-2 and none of them was found to be positive.

Rufloxacin (MF-934): in vitro and in vivo antibacterial activity.

Rufloxacin (MF-934) is a new quinolone which shows in vitro antibacterial activity against E. coli, Salmonella, Klebsiella, Proteus and Staphylococcus spp. Lower in vitro activity was observed with Pseudomonas, Serratia, Enterobacter and the streptococci group D. The antimicrobial activity of MF-934 in vitro is higher than that of nalidixic acid but lower than that of ciprofloxacin, ofloxacin, pefloxacin or norfloxacin. The protective effects of MF-934 in systemic infections in mice are lower than those of ciprofloxacin and ofloxacin. In respiratory infections in rats and in subcutaneous infections in guinea-pigs, the protective effects of MF-934 are of the same order as ciprofloxacin and ofloxacin. This is probably due to the pharmacokinetic properties of MF-934, i.e. the long half-life and tissue concentrations higher than plasma levels.

Evaluation of BACTEC system for urine culture screening.

We compared urine culturing performed by the calibrated loop method with a screening system (BACTEC). A total of 852 urine specimens were examined by both the conventional loop method and the BACTEC system. With the loop method, 193 (22.6%) urine samples were positive, whereas with the BACTEC system, 185 (21.7%) were positive (sensitivity, 96.01%). At a breakpoint of 10(4) CFU/ml, eight false-negatives were detected (sensitivity, 87.09%), and at a breakpoint of 10(5) CFU/ml, four false-negatives were observed (sensitivity, 97.6%). The specificity of the BACTEC system was 100%. We propose the BACTEC method as an effective alternative to the other growth-dependent screening tests for bacteriuria.

Reduced virulence in ciprofloxacin-resistant variants of Pseudomonas aeruginosa strains.

Pseudomonas aeruginosa strains resistant to ciprofloxacin were obtained from parental strains by serial transfer through subinhibitory concentrations of the drug. They showed reduced virulence for mice, and also increased sensitivity to aminoglycosides.

[Microbiological aspects of urinary infections in hospitalized and ambulatory elderly patients]. / Aspetti microbiologici delle infezioni urinarie nell'anziano ospedalizzato ed ambulatoriale.

The authors studied the microorganisms found in urocultures of three groups of elderly patients giving an exact map of the microbiology and epidemiology of the urinary tract infections of elderly patients. They shown also the calibrated loop seeding method as the most efficient to evaluate low bacterial concentration in urines which in these patients are significant.