Search results for "bacteria."

Evidence of enhanced bacterial invasion during Diplostomum spathaceum infection in European grayling, Thymallus thymallus (L.)

2006

Farmed grayling, Thymallus thymallus (L.), are susceptible to atypical Aeromonas salmonicida (aAS) infections. Interactions between bacteria and parasites were studied using grayling subjected to concomitant exposure to aAS bacteria and the digenean parasite Diplostomum spathaceum. Atypical AS was detected from fish by a combination of bacterial cultivation and polymerase chain reaction techniques. A detection level of 17 aAS cells per 100 mg intestine tissue sample was obtained. Concomitant bacterial exposure did not enhance the severity of grayling eye rupture and nuclear extrusion induced by D. spathaceum, but D. spathaceum invasion into grayling increased the proportion of fish carrying…

Immunostimulants in prevention of columnaris disease of rainbow trout, Oncorhynchus mykiss (Walbaum).

2009

Chondroitin AC lyase activity is related to virulence of fish pathogenic Flavobacterium columnare.

2006

The virulence of eight Flavobacterium columnare strains was studied to find correlations between several virulence-related factors and virulence. Virulence was tested in vivo using rainbow trout, Oncorhynchus mykiss (Walbaum). Suggested virulence-related factors such as production of the degradative enzyme chondroitin lyase, plasmid occurrence and adhesion capability were studied in vitro. Infection with the four most virulent strains resulted in 95-100% mortality within 114 h. Chondroitin lyase activity was found to be significantly related to the virulence of the strains at 25 degrees C and it was also shown to be temperature-dependent, being higher at 25 degrees C than at 20 degrees C. V…

Paenibacillus larvae Chitin-Degrading Protein PlCBP49 Is a Key Virulence Factor in American Foulbrood of Honey Bees

2014

Paenibacillus larvae, the etiological agent of the globally occurring epizootic American Foulbrood (AFB) of honey bees, causes intestinal infections in honey bee larvae which develop into systemic infections inevitably leading to larval death. Massive brood mortality might eventually lead to collapse of the entire colony. Molecular mechanisms of host-microbe interactions in this system and of differences in virulence between P. larvae genotypes are poorly understood. Recently, it was demonstrated that the degradation of the peritrophic matrix lining the midgut epithelium is a key step in pathogenesis of P. larvae infections. Here, we present the isolation and identification of PlCBP49, a mo…

Prevalence and Antimicrobial Resistance of Escherichia coli, Enterococcus spp. and the Major Foodborne Pathogens in Calves in Latvia

2018

The aim of the present study was to detect the prevalence and antimicrobial resistance of fecal indicators and major foodborne pathogens in feces of calves and to identify the factors associated with increased prevalence of resistant bacteria on farms. Altogether, 180 rectal swabs were collected from 18 farms in Latvia. Samples were investigated to detect the prevalence and antimicrobial resistance of Escherichia coli, Enterococcus spp., Listeria monocytogenes, Yersinia enterocolitica, Salmonella spp., Staphylococcus aureus, and Campylobacter spp. Among all, 64% (74/110) of commensal E. coli, 100% (78/78) Enterococcus faecalis and 96% (22/23) Enterococcus faecium isolates were resistant at …

Occurrence of Drug-Resistant Bacteria in Two European Eel Farms

2005

ABSTRACT The occurrence of strains that are resistant to oxolinic acid, oxytetracycline, sulfamethoxazole-trimethoprim, and nitrofurantoin among heterotrophic bacteria, including human and fish pathogens, in two freshwater eel farms was investigated. High levels of individual- and multiple-drug-resistant bacteria were detected, although sampling events were not correlated with clinical outbreaks and drug therapy.

Interactions between bacteria and Cryptosporidium molnari in gilthead sea bream (Sparus aurata) under farm and laboratory conditions

2006

The possible interaction of Cryptosporidium molnari and bacteria in gilthead sea bream (Sparus aurata) was studied. Epidemiological data from a pathological survey under farm conditions were analyzed. In addition, parasite and bacteria burdens were studied in experimental models in which naturally and experimentally parasitized fish were challenged with a particular strain of Vibrio harveyi (H57). All the bacteria species present were studied. Under farm conditions, the parasite was more prevalent when mortality or morbidity cases (study C) occurred than in randomly sampled fish (study B). In study C, parasite abundance was significantly higher in bacteria-negative fish, and total bacteria …

Extended-Spectrum ß-Lactamase, AmpC-Producing, and Fluoroquinolone-Resistant Escherichia coli in Retail Broiler Chicken Meat, Italy.

2015

Background: Globally, antimicrobial drug-resistant Escherichia coli is among the most common etiological agents of invasive disease in humans. In Europe, increasing proportions of infections due to third-generation cephalosporins and/or fluoroquinolone-resistant extraintestinal pathogenic E. coli (ExPEC) strains are reported. E. coli from poultry are those more closely linked to human E. coli, but lack of reliable data makes it difficult to assess the attributable risk of different food sources. In the present study, our objective was to investigate the antimicrobial resistance profile, phylogenetic background, and virulence factors of E. coli isolates from broiler chicken meat sold at reta…

Occurrence of selected antibiotics and antiretroviral drugs in Nairobi River Basin, Kenya.

2015

In this paper, we investigated the occurrence of three antibiotics (sulfamethoxazole, trimethoprim and ciprofloxacin) and three antiretroviral (lamivudine, nevirapine and zidovudine) drugs in the Nairobi River Basin, Kenya. The analytical procedure involved extraction using solid phase extraction followed by liquid chromatography-electrospray ionization tandem mass spectrometry (SPE-LC-ESI-MS/MS). In this study, 40 sites were selected for sampling, including 38 sites along the rivers and 2 wastewater treatment effluent sites. All the studied compounds were detected with sulfamethoxazole having the highest detection frequency of 97.5% and ciprofloxacin had the lowest at 60%. The results show…

Influence of rearing conditions on Flavobacterium columnare infection of rainbow trout, Oncorhynchus mykiss (Walbaum).

2005

The influence of rearing conditions on Flavobacterium columnare infection of rainbow trout, Oncorhynchus mykiss (Walbaum), was studied experimentally in the laboratory and at a fish farm. In experiment I, the effect of parasitic infection on columnaris disease was studied using F. columnare carrier fish. The fish were exposed to Diplostomum spathaceum cercariae and a set of other stressors in order to induce clinical columnaris infection. Parasitic infection and other stressors failed to induce the disease. Disease occurred when the fish were challenged with F. columnare, but D. spathaceum infection did not enhance the severity of the infection. In experiment II, the influence of rearing de…