Brucella canis

Artículo de publicación IS

Antimicrobial resistance monitoring in cattle in Chile using E. coli as the indicator bacteria

Antimicrobial resistance is an important worldwide public health problem having a negative impact on the struggle against bacterial diseases. The WHO indicates that there exists evidence that livestock are a reservoir for resistant bacteria and that medical physicians and veterinarians must work together on this problem. The aim of the present study was to monitor the antimicrobial resistance in cattle, using E. coli as the indicator bacteria. Fifty E. coli strains were isolated from caecal contents of dairy cattle (Group I) and 72 from beef cattle (Group II). The Minimal Inhibitory Concentrations to eight antimicrobial drugs were determined. The highest resistance percentages (86%) were observed in group I strains; whereas in beef cattle this value was under 11%. In the Group I strains the major levels of resistance were observed against ciprofloxacin, ceftiofur, enrofloxacin and oxitetracycline and in Group II, strains resistant to sulfamethoxazol/trimethoprim were observed. High mu

Stability inside hen eggs of a Salmonella enterica serovar enteritidis bacteriophage

Background: Bacteriophages are viruses that infect bacteria and therefore are widespread in nature. Those that lyse the pathogen Salmonella enterica serovar Enteritidis (SE) should be expected in niches in which this bacterium thrives, among others the avian egg. Furthermore, bacteriophages could remain viable in this milieu. Results: Upon artificially infecting hen eggs with the SE bacteriophage f18 we found that the bacteriophage titer remains stable at least for up to 144 hrs post-infection, both in yolk and albumen at 25°C. Conclusion: Bacteriophage f18 withstands the physico-chemical conditions of the egg inner milieu and could be considered for SE-controlling measures in the poultry industr

Health status of free-living pigeons in the city of Santiago

A total of 100 free-living urban pigeons (Columba livia) were captured in the city of Santiago, Chile, in order to evaluate, for the first time, their health status. Negligible antibody titres (1 to 3 log(2)) were detected in 22% of the birds against a strain of the paramyxovirus (PMV) serotype 1. No pigeons had antibodies against PMV serotype 7 and avian influenza. Salmonella sp. belonging to serogroups B and D were isolated from the intestinal tract of three pigeons (3%). The protozoa Haemoproteus columbae, Plasmodium sp., and Leucocytozoon sp, were not detected in any pigeons. Trichomonas gallinae was detected in 11%, without observation of either clinical signs or gross pathological changes at necropsy. Sixty-seven percent of the birds showed the presence of the chewing lice Columbicola columbae and Campanulotes bidentatus compar, and 1% harboured the mite Laminosioptes cysticola, Seven species of nematodes were identified. The frequency at which each species was detected was; Tetrameres sp, (14%), Capillaria annulata (1%), Capillaria columbae (11%), Capillaria obsignata (1%), Ascaridia columbae (5%), Dispharynx spiralis (2%), and Gongylonema ingluvicola (2%), The class Cestoda, found in one pigeon, was represented by the species Aporina delafondi. No trematodes were detected in the sampled birds

Una mezcla de bacteriófagos reduce los recuentos de Salmonella enterica serovar Enteritidis en tejidos de salmón fresco y ahumado

The use of bacteriophages for the biocontrol of food-borne pathogens is increasingly gaining acceptance. In this study, the effectiveness of bacteriophages to reduce Salmonella Enteritidis counts was evaluated in raw and smoked salmon tissues. Groups of 25 samples each were contaminated with S. Enteritidis, treated with a phage mix and then incubated for ten days at 18 °C and 4 °C. A signifi cant bacterial reduction was obtained on days 3, 6 and 10 in raw salmon samples incubated at 18 °C (from 0.75 to 3.19 log10 CFU/g) and at 4 °C (from 2.82 to 3.12 log10 CFU/g), whereas in smoked salmon lower reductions were achieved (from 1.02 to 1.96 log10 CFU/g at 18°C and from 0.50 to 1.16 log10 CFU/g at 4 °C). These results show the potential effectiveness of this bacteriophage cocktail as a biocontrol agent against S. Enteritidis in raw and smoked salmon tissues.El uso de bacteriófagos en el biocontrol de patógenos está adquiriendo cada vez más aceptación. En este estudio se evaluó la efectividad de bacteriófagos en la reducción de los recuentos de Salmonella Enteritidis en salmón fresco y ahumado. Para ello, 25 muestras por grupo fueron contaminadas con S. Enteritidis, tratadas con una mezcla de bacteriófagos e incubadas durante 10 días a 18 °C o a 4 °C. A los días 3, 6 y 10 se obtuvo una reducción signifi cativa de los recuentos de S. Enteritidis en las muestras de salmón fresco incubadas a ambas temperaturas: la reducción fue de entre 0,75 y 3,19 log10 UFC/g a 18 °C y de entre 2,82 y 3,12 log10 UFC/g a 4 °C. En salmón ahumado las reducciones fueron menores (entre 1,02 y 1,96 log10 UFC/g a 18 °C y entre 0,50 y 1,16 log10 UFC/g a 4 °C). Los resultados indican que estos bacteriófagos constituyen una potencial herramienta de biocontrol de S. Enteritidis en tejidos de salmón fresco y ahumado

Detection and Characterization of Enterohaemorrhagic Escherichia coli in Slaughtered Cattle

Artículo de publicación ISIFecal samples from slaughtered cattle were studred for enterohaemorrhagic E&vichia co/i (EHEC) by DNA hybridization with biotin-labelled DNA probes specific for the EHEC virulence plasmid, Shigalike toxin I (SLT I), Shiga-like toxin I1 (SLT 11) and eae gene. Among 136 animals analysed, 47 (34.5%) were found to carry EHEC. The cytotoxic genotypes observed for EHEC strains were: 60.4% SLT I, 12.5% SLT I1 and 10.4% SLT I+SLT 11; 16.7% resulted SLT I and SLT I1 negative. A total of 14 out of 48EHEC strains (29.2%) hybridzed with a fimbrial probe and 14 of 48 strains with an em probe. An important number of strains (18 out of 48) belonged to serogroups 0157,026 and 01 11, serogroups also commonly isolated from haemolytic uremic syndrome cascs in Chile. While EHEC isolates from the same animal were usually of the same serogroup, one animal was found to carry two EHEC strains of drfferent serogroups. A total of 50'Yn of EHEC strains were sorbitol negative, irrespective of the 0 serogroup or EHEC genotypic profile. Results obtained in this study strongly suggest that cattle in Chile are a reservoir of EHEC associated with disease in humans.Fondecyt No 195073