A simultaneous outbreak of Serratia marcescens and Klebsiella pneumoniae in a neonatal intensive care unit

We describe two concurrent outbreaks of Serratia marcescens and Klebsiella pneumoniae in a neonatal intensive care unit (NICU). Over a 16-month period, a total of 27 infants were either colonized (N=14) or infected (N=13). There were 15 cases of S. marcescens and 11 cases of K. pneumoniae. Both micro-organisms were involved in one fatal case. Seven preterm babies developed septicaemia, two had bacteraemia, three had respiratory infections and one had purulent conjunctivitis. The S. marcescens and K. pneumoniae isolates were investigated by three molecular methods: enterobacterial repetitive intergenic consensus polymerase chain reaction (PCR), arbitrary primed PCR with M13 primer, and random amplification of polymorphic DNA. Different patterns were found in the 16 S. marcescens epidemic isolates from 16 newborn infants. The major epidemic-involved genotype was linked to the first nine cases and this was subsequently replaced by different patterns. Eight different typing profiles were also determined for the 13 K. pneumoniae isolates from 12 newborn infants. Four K. pneumoniae bacteraemic strains proved to be identical. In conclusion, the typing results revealed that two different micro-organisms (S. marcescens and K. pneumoniae) were simultaneously involved in invasive nosocomial infections in preterm newborns. Two simultaneous clusters of cases were documented. Heterogeneous genotypes among both species were also demonstrated to be present in the NICU at the same time. A focal source for both micro-organisms was not identified but cross-transmission through handling was probably an important route in this outbreak. Strict adherence to handwashing policies, cohorting, isolation of colonized and infected patients, and rigorous environmental hygiene were crucial measures in the containment of the epidemic.

Genetic basis of tetracycline resistance in food-borne isolates of Listeria innocua

Eleven of 12 tetracycline-resistant Listeria innocua strains, isolated from chicken or turkey frankfurters and mozzarella cheese, were shown to carry DNA sequences which hybridized with the Tet M probe; of these, two strains also hybridized with Tet K. The remaining strain hybridized with the Tet K probe only. The Tet M determinant appeared to be located on the chromosome; in one case, it was transferable by conjugation to recipients Listeria monocytogenes, Listeria ivanovii, and Enterococcus faecalis.

A comparative study of a surgical method and scaling and root planing using the Odontoson

This investigation compared a traditional periodontal surgical method with a non-surgical treatment of scaling and root planing by an ultrasonic device (Odontoson M) using irrigation with an iodised solution. 8 adult patients with periodontal disease were each treated at 2 randomly chosen quadrants by a Widman flap type surgical technique, and the remaining non-surgically. The patients then attended bi-monthly oral hygiene sessions over a period of 1 year. At that stage, clinical evaluation revealed that the Odontoson M plus an ionized irrigant solution achieved a statistically comparable outcome to that of surgical treatment, even in the pockets initially up to 7 mm in depth.

In-vitro studies of two 5-nitroimidazole derivatives

This paper reports the findings obtained using two new compounds belonging to the 5-nitroimidazole family: sulphuridazole (V1) and sulphonidazole (V2). We first assessed their antimicrobial activity on Clostridia spp. and then extended the study to Gram-positive and Gram-negative aerobic microorganisms and to Candida albicans. Their MICs were compared with those of metronidazole. The findings show that the antibacterial and antimycotic activity of sulphonidazole is greater than that of sulphuridazole, while metronidazole is not active against any aerobic organism. It also emerges that the NO2 group is indispensable for all the microorganisms assayed and that sulphuridazole and sulphonidazole are the first two 5-nitroimidazoles active against C. albicans. The redox potentials of the 5-nitroimidozoles studied suggest that their action mechanism is mainly based on redox processes.

Interactions with lectins and agglutination profiles of clinical, food, and environmental isolates of Listeria

On the basis of preliminary trials with 14 collection strains of Listeria, five lectins (Canavalia ensiformis, concanavalin A; Griffonia simplicifolia lectin I; Helix pomatia agglutinin; Ricinus communis agglutinin; and Triticum vulgaris wheat germ agglutinin) were selected to set up a microtiter agglutination assay. The lectin agglutination profiles of 174 clinical, food, and environmental strains of Listeria monocytogenes, Listeria innocua, and Listeria seeligeri were investigated. Data on the standard determination of the antigenic structure were available for clinical strains; nonclinical isolates were assigned to serogroup 1 or 4 with commercial antisera. The listeria-lectin interaction was related to serological type rather than species; in particular, the strains assigned to serogroup 1 or belonging to serovars 1/2a, 1/2b, 1/2c, 3a, 3b, and 7 were never agglutinated by G. simplicifolia lectin I. The five-lectin set proved to be capable of detecting differences between serologically identical isolates of L. monocytogenes. Of the 150 isolates of this species, 144 were distributed over 15 different lectin agglutination profiles and 6 autoagglutinated, the overall typeability being 96%. However, the profiles encountered among L. monocytogenes isolates were not randomly distributed. With strains assigned to serogroup 1 or belonging to serovars 1/2a, 1/2b, 1/2c, and 3b, the clinical isolates fell into only two of the eight patterns recorded overall; with strains of serogroup 4 and serovar 4b, food and environmental isolates were distributed over eight of the nine patterns found in total, while clinical isolates were distributed over five patterns. In a comparative study of 15 epidemiologically relevant isolates of L. monocytogenes from five distinct outbreaks, strains with identical phage types and/or DNA fingerprints displayed identical lectin profiles. The heterogeneity of agglutination profiles may form the basis of a new approach to L. monocytogenes typing.

Search for viruses in the CSF of patients with acute neurological disorders: possible involvement of beta-and gamma-herpesviruses

In the years 1999-2001, 868 samples of cerebrospinal fluid (CSF) from as many patients with acute neurological manifestations of suspected viral origin were analysed for the presence of viruses at the Centre for the Diagnosis of Viral Diseases of the University of Modena and Reggio Emilia. Neurological patients included 788 immunocompetent subjects and 80 patients with impaired immunity due to human immunodeficiency virus (HIV) seropositivity. Of the CSF samples, 125 (15.8%) were positive for one or more viruses among the immunocompetent patients, whereas 33 (41.1%) were positive among the HIV cohort. DNA and RNA viruses were detected in the first group of CSF samples whereas only DNA viruses were found in the second group. In immunocompetent patients the frequency of enteroviruses prevailed over that of other RNA virus families (p = 0.001) and that of herpesviruses over the frequency of other DNA virus families (p = 0.001). Among herpesvirus members, the Epstein-Barr gamma-herpesvirus prevailed on alpha-herpesviruses in each of the two groups of patients (p = 0.05 in the immunocompetent group and p = 0.006 in HIV-positive patients). The clinical relevance both of this virus and of beta-herpesviruses as a cause of neurological disorders is discussed.

[Active clinical surveillance for detection of Legionnaires' disease: implications for health care structures]

In an university hospital of about 900 beds, a clinical surveillance was activated to detect cases of Legionnaires' disease in patients affected by community and/or nosocomial-acquired pneumonia. In the hospital Legionella spp was detected in the hot water distribution system and various disinfecting and control procedures were adopted to reduce contamination. Contemporary, the clinical surveillance began with the systematic detection of Legionella urinary antigen among recovered pneumonia, seroconversion as confirmation test and the collection of respiratory secretions or other biological materials to isolate the microorganism in patients positive to the urinary antigen. From September 2003 to May 2005, 486 pneumonia were followed, 98 of which considered of nosocomial origin. In total, 15 cases of community-acquired Legionnaires' disease were detected by the urinary test, whereas no cases of nosocomial origin were found. The characteristics of the detected cases are described in comparison with the other pneumonia and the surveillance cost was evaluated. The systematic clinical surveillance for Legionella infections is feasible with limit costs, allows to detect community-acquired cases otherwise unknown and to ascertain the absence/presence of nosocomial-acquired pneumonia, irrespective of the environment contamination.

[Sepsis caused by Corynebacterium xerosis in neonatology: report of a clinical case]

The pathogenicity of the nondiphtheria corynebacteria, most commonly known as coryneform bacteria in humans has been recognized in the last two decades. Corynebacterium xerosis is part of the normal flora of the skin, nasopharynx, conjunctives and it has recently been isolated from vaginal swabs. During the last few years, there has been an increased number of case reports claiming an association of C. xerosis with diseases, like septicemia, endocarditis, pleuropneumonia, peritonitis, osteomyelitis, septic arthritis, mediastinitis, meningitis, ventriculitis specially in immunocompromised patients or surgical patients. Infections due to C. xerosis have been reported rarely in newborn. We report a case of sepsis due to C. xerosis in a newborn without evident immunodeficiency. Our case further support the recognition of C. xerosis as a human pathogen and reinforces the fact that it should not be routinely considered as a contaminant.

Antiviral and antiproliferative activity in vitro of some new benzimidazole derivatives

The antiviral and antiproliferative activity of new compounds having n-benzenesulphony 1-2 (2 or 3-pyridylethyl) benzimidazole as a base structure were studied in vitro. Their antitumour activity against human chronic myeloid leukaemia cells was evaluated and compared with that of equimolar doses of daunorubicin. Only compound 7a, with the presence of both the pyridyl moiety bound at the ethylenic bridge in C-2 of benzimidazole and the nitro-group in the benzene ring, displays a selective antiproliferative effect against certain leukaemia cells and a good antiviral activity especially towards the Coxsackie B5 virus. However, it should be noted that, in the case of hydroxybenzyl-benzimidazole, resistance also builds up to compound 7a, the Coxsackie B5 virus developing resistance to it after about ten runs. Cytotoxicity tests show that many of these substances are well tolerated by the VERO cells. The mechanism of action is still unclear.

Cytologic diagnosis of Acanthamoeba keratitis. Report of a case with correlative study with indirect immunofluorescence and scanning electron microscopy

We describe a case of Acanthamoeba keratitis in a 20-year-old woman who wore disposable soft contact lenses. The diagnosis was made initially on the basis of a periodic acid-Schiff-stained corneal smear and subsequently confirmed by scanning electron microscopy and immunofluorescence. The patient was successfully treated with a combination of 0.053% polyhexamethylene biguanide and miconazole. Cytologic study and culture of corneal scrapings is relatively painless and inexpensive and may therefore be used for successful diagnosis and follow-up.

[A case of Hodgkin's disease complicated by Strongyloides stercoralis infestation]

A case of Hodgkin's disease complicated by severe Strongyloides stercoralis infection is reported. Strongyloides is an opportunistic parasite that can produce particularly dangerous clinical pictures by autoinfestation in patients with impaired immunity. The appearance of aspecific gastrointestinal symptoms in such patients should trigger careful examination to discover the presence of parasites as well as the more common pathogenic bacteria. reduced among the elderly.

Keratomycosis with an unusual etiology (Rhodotorula glutinis): a case report

A case of deep keratomycosis with isolation of Rhodotorula glutinis is discussed. Keratoplasty, done immediately, prevented panophthalmitis and cured the patient. The etiology and pathogenesis of fungal keratitis is examined.

Role of chemotherapeutic antagonism in opportunistic infections

The most widely-known anti-tumor drugs often induce marked immunosuppression which can give rise to one or more sepses. Anti-infection measures immediately applied can sometimes prove largely ineffective or even useless, the patient dying not as a result of the spread of the tumour but as a direct consequence of opportunistic infection. We postulate that antagonism between anti-tumour and antimicrobial drugs may also play an important part in this. By way of illustration of this hypothesis, we have studied the action of a number of known inhibitors of peptidoglycan synthesis and of DNA-gyrases on certain strains of Gram-positive and Gram-negative microorganisms cultured in medium containing various concentrations of some of the best-known anti-tumour antimetabolites. The experimental data show that antimicrobial and anti-tumour drugs can sometimes induce synergic or indifferent chemotherapeutic interactions with many bacteria, while in others the effect is antagonistic. In practice, the action of the drugs could lead to bacterial selectivity, which, in conjunction with immunosuppression and the presence of resistant strains, could favour the evolution of opportunistic infection.

Evaluation of a vero cell toxicity test to detect EHEC infection

An epidemiologic investigation was carried out in Modena (Italy) to evaluate the prevalence of faecal VEROtoxin (FVT) in diarrhoeal stool specimens. One thousand and sixty-six stool specimens, submitted to the Clinical Microbiology Laboratory of the University Hospital of Modena, were collected and faecal filtrates tested for neutralizable cytotoxin by a toxicity test on VERO cells. Cytopathic effect on VERO cells was produced by 301 stool specimens (28%); neutralizable VT was detected in 40 (13%) out of 301 positive samples (3.7% of 1066 specimens). The prevalent FVT type was VT2 (50%), followed by VT1 (32.5%) and VT1+2 (17.5%). We evaluated an assay that detects both VTs directly from stool specimens to demonstrate that enterohemorrhagic strains (EHEC) should be considerated a causative agent of sporadic non-bloody diarrhoea. Our results suggest that toxin neutralization assay is a sensitive and specific technique and may be used as an alternative method to diagnose diarrhoeal infections caused by EHEC.