Case-control study to detect protective factors on pig farms with low Salmonella prevalence

The prevalence of Salmonella in UK pigs is amongst the highest in Europe, highlighting the risk to public health and the need to investigate on-farm controls. The objective of this study was to identify factors currently in operation on pig farms that had maintained a low Salmonella seroprevalence. For this purpose a case-control study was designed and pig farms with a low (\u3c10%) seroprevalence were compared against two randomly selected control farms, sharing the same geographical region and production type. A total of 11,452 samples, including pooled and individual floor faeces and environmental samples from pigs and their vicinity were tested and prevalence examined. In addition, detailed questionnaires were completed during the farm visits to collect descriptive data for risk factor analysis. It was shown that control farms had significantly higher prevalence compared to the case farms (19.4% and 4.3% for pooled and 6.7% and 0.1% for individual samples, respectively). The two risk factor analyses identified multiple variables associated with Salmonella prevalence including variables related to feed, effectiveness of cleaning and disinfection, biosecurity and batch production

Prebiotic and probiotic agents enhance antibody-based immune responses to Salmonella Typhimurium infection in pigs

Salmonellosis causes significant economic losses to the pig industry and contaminated pork products are an important source of Salmonella for humans. The EU ban on the use of antibiotic growth promoters in pig production, and the emergence of antibiotic resistance has meant there is a pressing need for alternative control strategies for pathogenic bacteria such as S. Typhimurium in pigs. Here, we determined the effects of prebiotic, probiotic and synbiotic diet regimes on antibody responses to oral Salmonella challenge of pigs. The data demonstrate that the inclusion of the probiotic Lactobacillus plantarum B2984 in the diet of piglets (∼1 × 1010 cfu/animal/day) enhanced serum IgM (P<0.001), IgG (P=0.001) and IgA (P=0.039) responses to S. Typhimurium infection including cross-reacting antibodies to S. Enteritidis. Similarly, inclusion of the prebiotic lactulose at 1% (w/w) of the feed on a daily basis in the diet enhanced serum IgM (P=0.010), IgG (P=0.004) and IgA (P=0.046) responses to S. Typhimurium infection and also cross-reacting antibodies to S. Enteritidis. Inclusion of both additives in the synbiotic diet also elicited an enhanced immune response with IgM (P=0.009) and IgG (P=0.046) levels being increased, however a significant interaction of the pre and probiotics was observed when considering the immune responses to S. Typhimurium (IgM P=0.004; IgG and IgA, P<0.001 for interaction). With respect to immune responses, the effects of pre or probiotic administration were the same or reduced in the synbiotic diet compared to when used in isolation. The data support the use of Lactobacillus plantarum B2984 or lactulose as strategies to contribute to the protection of weaned piglets from zoonotic bacterial pathogens, but caution must be taken when combining dietary supplements as combinations can interact

Zastosowanie pylistych węgli aktywnych do usuwania materii organicznej z wody podziemnej

The article presents research results of the introduction of powdery activated carbon to the existing technological system of the groundwater treatment stations in a laboratory, pilot plant and technical scale. The aim of the research was to reduce the content of organic compounds found in the treated water, which create toxic organic chlorine compounds (THM) after disinfection with chlorine. Nine types of powdery active carbons were tested in laboratory scale. The top two were selected for further study. Pilot plant scale research was carried out for the filter model using CWZ-30 and Norit Sa Super carbon. Reduction of the organic matter in relation to the existing content in the treated water reached about 30%. Research in technical scale using CWZ-30 carbon showed a lesser efficiency with respect to laboratory and pilot-plant scale studies. The organic matter decreased by 15%. Since filtration is the last process before the individual disinfection, an alternative solution is proposed, i.e. the second stage of filtration with a granular activated carbon bed, operating in combined sorption and biodegradation processes. The results of tests carried out in pilot scale were fully satisfactory with the effectiveness of 70–100%.W artykule przedstawiono wyniki badań w skali laboratoryjnej, półtechnicznej i technicznej nad wprowadzeniem do istniejącego układu technologicznego stacji uzdatniania wody podziemnej, pylistego węgla aktywnego. Celem badań było obniżenie zawartości występujących w wodzie uzdatnionej związków organicznych, które po procesie dezynfekcji chlorem tworzą toksyczne związki chloroorganiczne (THM). W skali laboratoryjnej przebadano 9 rodzajów pylistych węgli aktywnych, z których dwa najlepsze wytypowano do dalszych badań. Badania w skali półtechnicznej realizowano na filtrze modelowym z zastosowaniem węgli: CWZ-30 i Norit Sa Super. Obniżenie materii organicznej w stosunku do jej dotychczasowej zawartości w wodzie uzdatnionej wynosiło ok.30%. Badania w skali technicznej z zastosowaniem węgla CWZ-30 wykazały nieco mniejszą skuteczność w odniesieniu do badań laboratoryjnych i badań w skali półtechnicznej. Obniżenie zawartości materii organicznej wyniosło ok. 15%. Ponieważ ostatnim procesem jednostkowym przed dezynfekcją jest filtracja, zaproponowano alternatywne rozwiązanie – drugi stopień filtracji ze złożem granulowanego węgla aktywnego, pracującego w połączonych procesach sorpcji i biodegradacji. Rezultaty badań zrealizowanych w skali półtechnicznej były w pełni zadowalające – skuteczność 70–100%

Evidence for systemic spread of the potentially zoonotic intestinal spirochaete Brachyspira pilosicoli in experimentally challenged laying chickens

Brachyspira pilosicoli is a potentially zoonotic anaerobic intestinal spirochaete that is one of several species causing avian intestinal spirochaetosis. The aim of this study was to develop a reproducible model of infection in point-of-lay chickens and compare the virulence of two strains of B. pilosicoli in a model using experimentally challenged laying chickens. Seventeen-week-old commercial laying chickens were experimentally challenged by oral gavage with either B. pilosicoli strain B2904 or CPSp1, following an oral dose of 10 % sodium bicarbonate to neutralize acidity in the crop. Approximately 80 % of the chickens became colonized and exhibited increased faecal moisture content, reduced weight gain and delayed onset of lay. Tissues sampled at post-mortem examination were analysed to produce a quantitative output on the number of spirochaetes present and hence, the extent of colonization. The liver and spleen were colonized, and novel histopathology was observed in these tissues. The infection model we report here has potential use in studies to improve our understanding of the mechanisms by which Brachyspira elicit disease in poultry and in testing novel intervention strategies

Lactobacilli Antagonize the Growth, Motility, and Adherence of Brachyspira pilosicoli: a Potential Intervention against Avian Intestinal Spirochetosis ▿

Avian intestinal spirochetosis (AIS) results from the colonization of the ceca and colorectum of poultry by pathogenic Brachyspira species. The number of cases of AIS has increased since the 2006 European Union ban on the use of antibiotic growth promoters, which, together with emerging antimicrobial resistance in Brachyspira, has driven renewed interest in alternative intervention strategies. Probiotics have been reported as protecting livestock against infection with common enteric pathogens, and here we investigate which aspects of the biology of Brachyspira they antagonize in order to identify possible interventions against AIS. The cell-free supernatants (CFS) of two Lactobacillus strains, Lactobacillus reuteri LM1 and Lactobacillus salivarius LM2, suppressed the growth of Brachyspira pilosicoli B2904 in a pH-dependent manner. In in vitro adherence and invasion assays with HT29-16E three-dimensional (3D) cells and in a novel avian cecal in vitro organ culture (IVOC) model, the adherence and invasion of B. pilosicoli in epithelial cells were reduced significantly by the presence of lactobacilli (P < 0.001). In addition, live and heat-inactivated lactobacilli inhibited the motility of B. pilosicoli, and electron microscopic observations indicated that contact between the lactobacilli and Brachyspira was crucial in inhibiting both adherence and motility. These data suggest that motility is essential for B. pilosicoli to adhere to and invade the gut epithelium and that any interference of motility may be a useful tool for the development of control strategies

Oral treatment of chickens with Lactobacillus reuteri LM1 reduces Brachyspira pilosicoli-induced pathology

Avian intestinal spirochaetosis (AIS) results from the colonization of the caeca and colon of poultry by pathogenic Brachyspira, notably Brachyspira pilosicoli. Following the ban on the use of antibiotic growth promoters in the European Union in 2006, the number of cases of AIS has increased, which, alongside emerging antimicrobial resistance in Brachyspira, has driven renewed interest in alternative intervention strategies. Lactobacillus-based probiotics have been shown to protect against infection with common enteric pathogens in livestock. Our previous studies have shown that Lactobacillus reuteri LM1 antagonizes aspects of the pathobiology of Brachyspira in vitro. Here, we showed that L. reuteri LM1 mitigates the clinical symptoms of AIS in chickens experimentally challenged with B. pilosicoli. Two groups of 15 commercial laying hens were challenged experimentally by oral gavage with B. pilosicoli B2904 at 18 weeks of age; one group received unsupplemented drinking water and the other received L. reuteri LM1 in drinking water from 1 week prior to challenge with Brachyspira and thereafter for the duration of the study. This treatment regime was protective. Specifically, B. pilosicoli was detected by culture in fewer birds, bird weights were higher, faecal moisture contents were significantly lower (P<0.05) and egg production as assessed by egg weight and faecal staining score was improved (P<0.05). Also, at post-mortem examination, significantly fewer B. pilosicoli were recovered from treated birds (P<0.05), with only mild–moderate histopathological changes observed. These data suggest that L. reuteri LM1 may be a useful tool in the control of AIS