Susceptibility to Bacteriocins of Multiresistant, mecA Gene Possessing Staphylococcus pseudintermedius Strains from Lesions on Dogs in Vojvodina (Serbia)

Aims: Staphylococci are considered commensal organisms; however, they can also cause diseases in animals. The species Staphylococcus pseudintermedius was originally isolated from the nares and anal mucosa of healthy dogs; nowadays, the incidence of methicillin-resistant S. pseudintermedius strains in dogs has increased, and this species has also become the most common cause of canine skin lesions. S. pseudintermedius were tested for their susceptibility to bacteriocins to show the potential of bacteriocins to eliminate/reduce S. pseudintermedius as a causative agent. Material and Methods: In this study, S. pseudintermedius were isolated from skin lesions on dogs of various breeds and ages in the Vojvodina region (Serbia) in the framework of our international co-operation. Results: S. pseudintermedius strains were identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry, and the species allocation was confirmed by genotypization and corroborated using phenotyping tests. The strains were multiresistant, involving methicillin-resistance. In addition, the mecA gene was detected in S. pseudintermedius strains, confirming the presence of a genetic feature for methicillin resistance. S. pseudintermedius strains produced large amounts of the enzymes alkaline phosphatase and acid phosphatase; they were low-grade biofilm forming (0.1 ≤ A₅₇₀ < 1.0), except S. pseudintermedius SPs1. All strains were susceptible to gallidermin (inhibition activity up to 204,800 arbitrary unit [AU]/mL); however, they were mostly resistant to enterocins. However, biofilm-forming S. pseudintermedius SPs1 was susceptible to enterocins (200 AU/mL). Conclusion: Establishing the susceptibility of multiresistant and mecA gene-possessing S. pseudintermedius strains to gallidermin is an innovative, original result; it provides a new opportunity for preventing/eliminating infection caused by those agents.

[Surgical treatment of pulmonary metastases--long-term results]

A group of 103 patients operated for lung metastases in the Surgical clinic of the FNsP of L. Dérer and in the II Surgical clinic of L. Pasteur is assessed in this work. Minor operations of atypical resection prevailed among the resections. The postoperative mortality in the whole group was 1.9%. The best long-term survival rates were reached in tumors primarily treated by chemotherapy and followed by the lung metastasectomy. All patients in this group suffered from testical tumors and their long-term survival rate was 69%. In tumor cases, where the metastasis was primarily removed by surgery, the long-term survival rate correlated with the literature data of 30%. When the prognostic factors were considered, the number of removed metachrone metastases being less than 3, appeared statistically significant from the point of view of the patient survival. Based on the evaluated results, it can be concluded that surgical treatment of the lung metastases performed within the interdisciplinary oncological concept, currently remains a generally accepted therapeutic procedure.

[Actinomycosis of the small intestine--an unusual cause of acute abdomen]

Actinomycosis is subacute or chronic disease manifested by a defined granulomatous inflammation with the development of infiltrates, abscesses and fistulae. A 35-year-old female patient was admitted and operated at the Second Surgical Clinic because of symptoms of diffuse peritonitis. Laparotomy revealed a duplicit tumour of the small intestine, an abscess of the abdominal wall in the left mesogastrium and pyoovarium bilaterale. 70 cm of the small intestine were resected, incision of the abscess and bilateral adnexotomy were performed. Histological examination revealed a suppurative, partly fibroproductive inflammation with an actinomycotic etiopathology. After antibiotic treatment the patient was discharged home, the gynaecologist removed an intrauterine device. Three months after the first operation the patient in a serious septic condition was readmitted to the clinic with signs of diffuse peritonitis. A double perforation of the small intestine was found and an end-to-end anastomosis was made after resection of the small intestine. The postoperative course was complicated by respiratory failure and failure of the circulation associated with septic shock and subsequent death. In the conclusion the authors emphasize the problem of preoperative diagnosis of the abdominal form of actinomycosis, its possible development in relation to intrauterine contraceptive devices and its clinical manifestation as acute abdomen.

[A splenic abscess of unknown etiology]

The authors describe the case-history of a 7-year-old female patient with a lienal abscess of unknown etiology. The patient was treated by classical splenectomy with a very good final outcome. The authors draw attention to the serious character of the disease even nowadays and to contemporary diagnostic and therapeutic possibilities.

Immunogenic and antigenic activity of an experimental oral rabies vaccine prepared from the strain Vnukovo-32/107

The immunogenic and antigenic activity of an experimental live oral rabies vaccine prepared from the strain Vnukovo-32/107 was evaluated on the basis of results obtained in 3 sets of experiments. These were carried out as model experiments on white mice, then on target animals--red foxes (Vulpes vulpes) and a related species--farm-bred polar foxes (Alopex lagopus). For quantitative determination of the immunogenic activity of the orally or subcutaneously administered rabies vaccines in model experiments on mice a method was used that had been developed in our laboratory. Antibodies were detected and quantified by an ELISA kit that had also been developed in our lab. Tenacity of the experimental vaccine (infectious tissue culture medium after yolk addition) was verified at different temperatures; the effects of storage temperature upon virus titre and immunogenic activity were investigated. An important part of the experiments--evaluation of the antigenic and immunogenic activity of the live vaccine at oral vaccination (vaccination baits, conditions simulating field vaccination) was carried out in foxes. The immunogenic activity (challenge experiments with a street virus on day 180 and 360 after vaccination) was evaluated in common foxes (Vulpes vulpes). The results document a high immunogenic and antigenic activity of the experimental live oral rabies vaccine. The strain Vnukovo-32/107 is suitable for the industrial manufacturing of vaccination baits. In the target species--common foxes challenged on day 180 after primovaccination an 83% protection was observed. Challenge on day 180 after revaccination (or day 360 after primovaccination), the orally immunized foxes proved to be 100% protected. For parallel evaluation of the immunogenic activity of an oral vaccine and for antibody titration it is recommended to employ the quantitative mice test and an ELISA technique, respectively.

Quantification of residual virulence of the Vnukovo-32/107 rabies virus vaccination strain

The present work summarizes the results of 11 groups of experiments carried out with the aim to complexly quantify the residual virulence of a cold mutant of the Vnukovo-32/107 rabies virus vaccination strain intended for the preparation of an oral rabies vaccine (Kamark) for the immunization of free-living carnivores. According to WHO prescriptions, residual virulence was quantified in experiments on carnivores, mainly red foxes (Vulpes vulpes)--the presumed target species, and farm-bred polar foxes (Alopex lagopus)--a related species. Further experiments were carried out in cats, dogs, non-target autochthonous micromammals, predatory birds (Microtus arvalis, Apodemus flavicollis, Falco tinnunculus) and in a large number of laboratory animals--white mice. At oral administration (including extremely high doses) the strain Vnukovo-32/107 proved to be apathogenic to the target carnivores--Vulpes vulpe and Alopex lagopus as well as cats, dogs and the autochthonous micromammals. For Falco tinnunculus the strain proved to be apathogenic even at intramuscular and intracerebral administration. The residual virulence of the Vnukovo-32/107 vaccination strain, also quantified by comprehensive model experiments on white mice of different weight categories that had been infected orally, subcutaneously, intramuscularly, intracerebrally, by contact, with ingestion of rabic material or by modelled immune suppression, proved to be extremely low-levelled. The strain under investigation revealed a high level of attenuation and a low level of residual virulence and proved to be suitable for the preparation of non-reactogenic oral vaccine intended for foxes, an extremely susceptible target species.