Selection of an Escherichia coli O157:H7 bacteriophage for persistence in the circulatory system of mice infected experimentally.

A bacteriophage lytic for Escherichia coli O157:H7 was isolated from bovine manure. Following in-vivo selection, the phage acquired the capacity to persist in the circulatory system of mice for at least 38 days. When mice were infected experimentally with E. coli O157:H7 (10(7) CFU/mouse), simultaneous injection of the mice with phage (10(8) PFU/mouse) cleared E. coli O157:H7 from the mice within 48 h.

Characterization of the second internal transcribed spacer of ribosomal DNA of Calicophoron daubneyi from various hosts and locations in southern Italy.

Isolates of the rumen fluke Calicophoron daubneyi (Digenea: Paramphistomidae) from various hosts and three locations in southern Italy were characterized genetically. The second internal transcribed spacer (ITS-2) of ribosomal DNA (rDNA) plus flanking 5.8S and 28S sequence (ITS-2+) was amplified from individual rumen flukes by PCR. PCR-linked restriction fragment length polymorphism (PCR-RFLP) analysis was performed using four different restriction endonucleases, and PCR products were sequenced. The PCR analyses from all the C. daubneyi specimens produced identical fragments, and the PCR-RFLP analyses did not show, with respect to any of the four restriction endonucleases, any differences between the C. daubneyi specimens. The sequence analyses of the ITS-2+ from each of the C. daubneyi specimens showed them all to be 428 bp, and composed of the entire ITS-2 sequence (282 bp) plus the two partial flanking conserved sequences, 5.8S (99 bp) and 28S (47 bp). No intra-specific variation was observed in the nucleotide composition of the ITS-2+ (homology=100%). There was, however, an observable inter-specific variation between the ITS-2+ of C. daubneyi and the ITS-2+ of both Calicophoron calicophorum (homology=97.2 %) and Calicophoronmicrobothrioides (homology=97.4 %), both previously deposited in the GenBank. The finding of the present study shows that, as has already demonstrated for other parasitic helminths, ITS-2 can serve as an effective genetic marker for the molecular identification of paramphistomes, and as a useful tool for developing molecular epidemiological techniques for the study of C. daubneyi transmission patterns and prevalence in definitive and intermediate hosts.

[Coxiella burnetii: what is the reality?]. / Coxiella burnetii: quale realtà?

After the Second World War, in Italy Q Fever or Coxiellosis has been shown a significant relevance, a recrudescence with an epidemic state for over ten years. Later, the infectious disease occurred as endemic since the 80s, the outbreaks were just isolated. Workflows analysis of some authors has demonstrated the spread out of the infection throughout Italian herds with a prevalence ranging from 1.2 per cent to 10 per cent. Our survey carried out throughout Campania area in cattle has shown a real positivity over 14 per cent performing the IFAT for the detection of IgG antibodies for Coxiella burnetii. Therefore, it has been so important to stress the influence of cattle farming management in stables as a real risk of Coxiellosis. For example, the Relative Risk (RR) has been registrated about 6.84 (2.18

Simultaneous identification of antibodies to Brucella abortus and Staphylococcus aureus in milk samples by flow cytometry.

Two flow cytometric assays are described herein. The single cytometric test (SCT) detects antibodies to either Brucella abortus or Staphylococcus aureus in the serum or milk of a cow or water buffalo. The double cytometric test (DCT) detects both anti-B. abortus and anti-S. aureus antibodies concurrently. In the SCT, the sample to be tested is incubated in succession with the antigen (either B. abortus or S. aureus) and the proper secondary antiserum (fluorescein isothiocyanate-labelled rabbit anti-cow immunoglobulin antiserum or rabbit anti-water buffalo immunoglobulin antiserum). In the DCT, the sample to be tested is incubated first with B. abortus and S. aureus antigens and then with the secondary antiserum. The B. abortus antigen used in the DCT is covalently bound to 3-microm-diameter latex particles. The difference in size between B. abortus and S. aureus permits the establishment of whether the antibodies are directed against one, the other, or both antigens. When compared to the complement fixation test, the SCT and DCT each show a specificity and a sensitivity of 100%. The SCT has been used previously to detect anti-S. aureus antibodies. Here its use is extended to the detection of anti-B. abortus antibodies. The DCT is described here for the first time. The DCT appears to be useful for large-scale brucellosis eradication programs. It offers the possibility of using one test to identify animals that are serologically positive for both B. abortus and S. aureus.

Detection of antibodies to Staphylococcus aureus in water buffalo milk by flow cytometry.

An assay has been developed to detect antibodies to Staphylococcus aureus in water buffalo milk by flow cytometry. The method was the protein A-deficient strain Wood 46 of S aureus incubated with milk samples and fluorescein-labelled rabbit anti-water buffalo antiserum. The assay can detect antibodies when the pathogen is not detectable by bacterial tests and can determine the antibody titre directly on undiluted samples.