, we collected 31 isolates of the rare serovar Salmonella bongori 48:z 35 :؊ in southern Italy. Twenty-four of the isolates were from cases of acute enteritis in humans. Pulsed-field gel electrophoresis analysis showed that all but one of our isolates were at least 80% similar. Our findings suggest that genetically related S. bongori 48:z 35 :؊ strains are endemically circulating in southern Italy.

Twenty-one Escherichia coli O157:H7 strains isolated in northern Italy from sporadic cases of hemolyticuremic syndrome and from cattle and food were characterized by virulence gene analysis, pulsed-field gel electrophoresis (PFGE) of XbaI-digested DNA, enterobacterial repetitive intergenic consensus (ERIC) sequence-based PCR (ERIC-PCR), and antibiotic resistance patterns and compared to 18 strains isolated in France from human cases of diarrhea, cattle, and the environment. Strains isolated in Sicily (southern Italy) from a local farm (one strain) and from calves just imported from France (11 strains) and Spain (six strains) were also typed. Whereas the eae and hlyA genes were always detected, Shiga toxin gene (stx) analysis showed some differences related to geographic areas. Isolates from northern Italy showed a high frequency of stx 1 and stx 2 , while strains isolated in France and from French and Spanish calves imported to Sicily more frequently possessed the stx 2c gene. The majority of the strains isolated in northern Italy were also resistant to one or more antibiotics, while most of the strains isolated in France and Sicily were fully susceptible. ERIC-PCR analysis was not able to differentiate the strains. PFGE typing after XbaI DNA digestion produced a total of 54 distinct restriction endonuclease digestion profiles (REDPs) among the 57 strains. Phylogenetic analysis was unable to cluster REDPs according to geographic origin. All epidemiologically related isolates showed either identical or >91% similar REDPs. Our findings suggest a peculiar circulation of antibiotic-resistant, genetically unrelated strains in northern Italy.

Fifty-five Escherichia coli strains belonging to enteropathogenic E. coli (EPEC) serogroups were examined for phenotypic and genetic factors associated with virulence. The strains were isolated in Italy from children with diarrhea and identified as EPEC by clinical laboratories using commercially available antisera. O:H serotyping showed that 35 strains (27 of O26, O111, and O128 serogroups) belonged to 11 serotypes considered to be classical EPEC O:H serotypes. The other 20 isolates were classified as 15 nonclassical EPEC O:H serotypes. All the potential EPEC virulence factors associated with bacterial adhesion (localized adherence, fluorescentactin staining test positivity, presence of the attaching and effacing [eaeA] gene), the production of verotoxin, and the positivity with the enterohemorrhagic E. coli probe were significantly more frequent among isolates belonging to classical than nonclassical serotypes. Strains displaying an aggregative adhesion and hybridizing with the enteroaggregative DNA probe were found in serogroups O86, O111, and O126. Verotoxin-producing isolates belonged to serogroups O26, O111, and O128. Only one of the isolates hybridized with the EPEC adherence factor (EAF) probe, but 33 strains gave positive results with the eae probe, confirming that the former is more suitable in epidemiological studies in European countries. These results indicate that up to 75% of strains identified as EPEC by commercial antisera may possess potential virulence properties and/or belong to classical EPEC O:H serotypes and suggest that O grouping is still a useful diagnostic tool for presumptive identification of diarrheagenic E. coli in clinical laboratories.

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Phylogenetic analysis of partial rpoB gene sequences of type and clinical strains belonging to different 16S rRNA gene-fingerprinting ribogroups within 11 species of enterobacteria of the genera Proteus, Morganella and Providencia was performed and allowed the definition of rpoB clades, supported by high bootstrap values and confirmed by ≥2.5 % nucleotide divergence. None of the resulting clades included strains belonging to different species and the majority of the species were confirmed as discrete and homogeneous. However, more than one distinct rpoB clade could be defined among strains belonging to the species Proteus vulgaris (two clades), Providencia alcalifaciens (two clades) and Providencia rettgeri (three clades), suggesting that some strains represent novel species according to the genotypes outlined by rpoB gene sequence analysis. Percentage differences between the rpoB gene sequence of the type strain of Proteus myxofaciens and other members of the same genus (17.3–18.9 %) were similar to those calculated amongst strains of the genus Providencia (16.4–18.7 %), suggesting a genetic distance at the genus-level between Proteus myxofaciens and the rest of the Proteus–Providencia group. Proteus myxofaciens therefore represents a member of a new genus, for which the name Cosenzaea gen. nov., is proposed.

Agrobacterium isolates from intravenous catheters of three hospitalized patients were initially identified as A. tumefaciens, but inability to produce 3-ketolactose revealed that two of them were A. vitis. However, rDNA analysis correlated all of the isolates to A. tumefaciens. Pulsed-field gel electrophoresis analysis ascertained the nosocomial transmission of the infection.

A coryneform bacterium was isolated from the bronchoalveolar aspirate of a patient with interstitial pulmonary inflammation. Commercial systems identified the isolate as Corynebacterium sp. or Aureobacterium sp./Corynebacterium aquaticum, but 16S rRNA gene analysis unequivocally attributed it to the genus Microbacterium. This represents the first documented case of Microbacterium pulmonary infection. Case reportA 44-year-old man underwent heart transplantation on 8 August 2000 as a consequence of ischaemic cardiomyopathy (previous extended anterior myocardial infarction). Transplantation and the post-operative course were uncomplicated and the patient was discharged on 31 August 2000 and prescribed a cyclosporin A, azathioprine and corticosteroid therapy (cyclosporin blood levels were expected to be 400 ng dl 21 ). Ten days later, the patient showed an acute organ rejection documented by endomyocardial biopsy (Grade 2, Dallas Classification, with diffuse and aggressive infiltrate) and was treated with high doses of intravenous corticosteroid (500 mg methylprednisolone per day for 3 days). Following this therapy, the rejection successfully reversed (Grade 1A at 1 month after treatment).Twelve days after corticosteroid treatment, the patient was readmitted with fever, neck pain, oesophageal discomfort during deglutition and a cough. At that time, the white blood cell count was 0?56 cells ml 21 with 80 % neutrophils, 15 % lymphocytes and a CD4/CD8 ratio of 0?4, thus showing intense immunosuppression. Fever quickly rose to 38?3 u C. Several blood and sputum cultures were negative for aerobic and anaerobic bacteria and for fungal cells. Before and after the transplant, the patient had been monitored for cytomegalovirus by the pp65 antigenaemia test, whose results were constantly negative. At the time of readmission, a further test for cytomegalovirus pp65 antigenaemia was performed and the result again was negative. A chest radiograph showed interstitial inflammation of the inferior left pulmonary lobe. After a few days, pleural effusion developed, as evidenced by physical examination. Computerized axial tomography examination confirmed pulmonary inflammation and pleural effusion, but excluded mediastine involvement. Initially, the patient was treated empirically with meropenem (500 mg three times per day), clarithromycin (500 mg per day), ciprofloxacin (200 mg twice a day) and fluconazole (150 mg per day), all intravenously, and oral trimethoprim/sulfamethoxazole (800 mg per day). This therapy did not lower the fever, nor did it attenuate the other symptoms. After 5 days, a selective bronchoalveolar washing was performed and the aspirate was examined. Direct Gram staining showed the presence of Gram-positive bacilli, whilst observation for Pneumocystis jiroveci (Pneumocystis carinii) after Giemsa and toluidine blue O staining yielded negative results. The aspirate was not checked for the presence of cytomegalovirus, but was cultured for aerobic and anaerobic bacteria, as well as for fungi. Culture on blood agar and ...

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