Pathomorphological, immunohistochemical and bacteriological findings in budgerigars (Melopsittacus undulatus) naturally infected with S. Gallinarum.

The present study describes the pathological and bacteriological findings and diagnosis by immunoperoxidase and immunofluorescence methods in budgerigars (Melopsittacus undulatus) naturally infected with Salmonella gallinarum obtained from three commercial budgerigar rearing farms. The course of the disease in young budgerigars was peracute or acute, whereas in adult budgerigars the disease was acute or chronic. Clinically, yellow-white diarrhoea was observed in the young budgerigars with the acute form. In the adult budgerigars with the acute and chronic forms, a decrease in feed and water consumption with loss in body condition together with greenish-yellow diarrhoea was generally noted. Peritonitis and pericarditis were the most common findings in young budgerigars at necropsy, while in adult budgerigars scattered grey-white necrotic foci were found in the livers. Histopathologically, the lesions in young budgerigars were characterized with fibrinonecrotic peritonitis and/or pericarditis and necrotic hepatitis. In adult budgerigars with acute infection, hepatic necrosis with focal heterophil infiltration was present; whilst lesions in the chronic cases were granulomatous in nature with the infiltration of macrophages, lymphocytes and histiocytes. For the detection of S. Gallinarum in formalin-fixed, paraffin-embedded tissues, the avidin-biotin peroxidase complex and immunofluorescence methods were used. Both methods showed bacteria to be localized in the liver, kidney, peritoneum, heart, spleen and intestines of both young and adult budgerigars. The results of the present study indicate that the avidin-biotin peroxidase complex method was more sensitive than the immunofluorescence method in the detection of the bacteria.

Molecular epidemiology and antimicrobial resistance mechanisms of methicillin-resistant Staphylococcus aureus isolated from bovine milk.

The aim of this study was to identify methicillin-resistant Staphylococcus aureus (MRSA) strains gathered from 2002 to 2006 from milk samples in Aydin region in Turkey. Among 93 S. aureus strains isolated from bovine milk with mastitis, 16 were resistant to methicillin. Methicillin-resistant S. aureus strains were studied further for their staphylococcal cassette chromosome mec (SCCmec) types, pulsotypes, spa and MLST types, antimicrobial susceptibilities, mechanisms of resistance and presence of Panton-Valentine leucocidin (PVL) toxin gene. The MRSA strains were multi-drug resistant. The susceptibility rates to antimicrobials tested were 0%, 0%, 0%, 0%, 6.25%, 16.25% and 56.25% for erythromycin, clindamycin, chloramphenicol, gentamicin, tetracyclin, ciprofloxacin and vancomycin, respectively. All tetracycline and gentamicin resistant strains carried tet(M) and aac(6)-aph(2) gene, respectively. Among macrolide-resistant isolates, nine had erm(A), and seven had both erm(A) and erm(B) genes. The molecular characterization by pulsed-field gel electrophoresis showed presence of three pulsotypes with their variants. The pulsotype B strains were type IV with SCCmec typing, and representative of pulsotype B was t190 by spa typing and ST8 by MLST typing. The strains with pulsotype A and C were SCCmec III, and representative of these pulsotypes was t030 by spa typing. The MLST type of pulsotype A was ST239 and pulsotype C was one allele variant of ST239. None of the isolates harboured the PVL gene. Presence of hospital-related MRSA strains may indicate transmission of these strains between human and animals. In case of clonal spread beside the infected animals' treatment of MRSA carrier, farm workers should also be considered. Hygienic measures and rational antibiotic use may avoid resistance selection, clonal dissemination of resistant strains and decrease losses because of mastitis in dairy herds.