Protective effect of Lactiplantibacillus plantarum LP5 in a murine model of colonisation by Campylobacter coli DSPV458

Thermotolerant Campylobacter species are the leading cause of foodborne bacterial diarrheal disease worldwide. Campylobacter coli, abundant in pigs and pork products, have been identified as a source of human infection. In this study, we propose the use of Lactiplantibacillus plantarum LP5 as a probiotic to reduce colonisation of this intestinal pathogen in a murine colonisation model of C. coli DSPV458. Six-week-old adult female Balb/cCmedc mice were housed in groups: Control, Campy and Pro-Campy. Control and Pro-Campy groups received antibiotics for 5 days and the Campy group for 12 days. Pro-Campy group was inoculated for 7 days with 8.78 log₁₀ cfu total of L. plantarum LP5 suspended in De Man, Rogosa and Sharpe broth. All groups were inoculated with 6.72 log₁₀ cfu of C. coli DSPV458 suspended in brain heart infusion broth. L. plantarum LP5 was recovered only in the Pro- Campy group. C. coli DSPV458 was recovered at higher levels in the Control and Campy groups. The differences with the Pro-Campy group were significant. As regards faeces, Control and Campy groups reached 7.41 and 7.84 log₁₀ cfu/g, respectively, and the Pro-Campy group only 4.62 log₁₀ cfu/g. In the caecum, Control and Campy groups reached 8.01 and 9.26 log₁₀cfu/g, respectively, and the Pro-Campy group only 4.51 log₁₀ cfu/g. In the ileum, Control and Campy groups reached 3.43 and 3.26 log₁₀ cfu/g, respectively, and the Pro-Campy group did not show detectable levels. The reduction of C. coli DSPV458 in the Pro-Campy group compared to the Control group in faeces, caecum and ileum was 99.55, 99.98 and 100%, respectively. Animals were maintained under normal health conditions, and haematological parameters were within the standard values for Balb/cCmedc. The incorporation of a probiotic generated a protective effect in the mice colonisation model. The protective effect would also apply to intestinal colonisation by indigenous enterobacteria. Therefore, the strategy used in this study is of great importance to understand the protection mechanisms in a murine model, as well as its application in food-producing animals.

Murine colonization model by Campylobacter coli DSPV458

AIMS

To generate a murine experimental model of colonization by Campylobacter coli DSPV458.

METHODS AND RESULTS

Twelve adult Balb/cCmedc female mice were housed in a treated group (T-G) and a control group (C-G) for 4 weeks. Both experimental groups received antibiotics for 5 days during the first week. The T-G was administered with 6.68log₁₀ CFU of C. coli DSPV458 by oesophageal gavage. Necropsies were performed weekly to evaluate translocation and intestinal colonization in the spleen and liver and in the ileum and cecum respectively. Samples were cultured to quantify intestinal microbiota members. Faeces were cultured weekly for a C. coli DSPV458 count. Campylobacter coli DSPV458 was isolated from all the inoculated mice. The recovered level of C. coli DSPV458 was, on average, 6.9 log₁₀ CFUg^-1 , 8.0 log₁₀ CFUg^-1 and 1.6 log₁₀ CFUg^-1 in faeces, cecum and ileum respectively. Colonization by C. coli DSPV458 does not alter the normal clinical and physiological status.

CONCLUSIONS

Campylobacter coli DSPV458 does not have an invasive capacity, and the model is suitable for evaluating strategies to reduce intestinal loads.

SIGNIFICANCE AND IMPACT OF STUDY

Farm animals have an important impact on thermotolerant Campylobacter transmission to humans. Extremely few colonization models by C. coli have been reported to date. In food-producing animals, infection is mild or absent and thermotolerant Campylobacter colonize the intestines of animals. Colonization models are specific models that do not cause infection as they do not generally result in diarrhoea or other signs of disease. Therefore, this model will allow to evaluate the evolution of colonization by thermotolerant Campylobacter and the alternative tools development to antibiotics that limit their colonization in food-producing animals.

In vitro screening and in vivo colonization pilot model of Lactobacillus plantarum LP5 and Campylobacter coli DSPV 458 in mice

The objective of this work was to determine the antibacterial effect of Lactobacillus plantarum strains of pork origin against Campylobacter coli strains, and to conduct experimental colonization pilot models in mice for both microorganisms. Inhibition assays allowed evaluation and selection of L. plantarum LP5 as the strain with the highest antagonistic activity against C. coli and with the best potential to be used in in vivo study. Adult 6-week-old female Balb/cCmedc mice were lodged in two groups. The treated group was administered with 9.4 log₁₀CFU/2 times/wk of L. plantarum LP5. L. plantarum LP5 was recovered from the feces and cecum of the inoculated mice. However, when bacteria stopped being administered, probiotic counts decreased. Experimental colonization with C. coli was carried out in five groups of mice. All animals were treated with antibiotics in their drinking water to weaken the indigenous microbiota and to allow colonization of C. coli. Four groups were administered once with different C. coli strains (DSPV458: 8.49 log₁₀CFU; DSPV567: 8.09 log₁₀CFU; DSPV570: 8.46 log₁₀CFU; DSPV541: 8.86 log₁₀CFU, respectively). After 8 h, mice inoculated with different C. coli strains were colonized because the pathogen was detected in their feces. L. plantarum LP5 tolerated the gastrointestinal conditions of murine model without generating adverse effects on the animals. C. coli DSPV458 colonized the mice without causing infection by lodging in their digestive tract, thus generating a reproducible colonization model. Both models combined could be used as protection murine models against pathogens to test alternative control tools to antibiotics.

Possible reservoirs of thermotolerant Campylobacter at the farm between rearing periods and after the use of enrofloxacin as a therapeutic treatment

Campylobacteriosis is a zoonosis and the most frequent cause of food-borne bacterial enteritis in humans. C. jejuni and C. coli are the most common species implicated in campylobacteriosis. Broilers and their products are considered the most important food sources of human infections. The aim of the present study was to evaluate the presence of thermotolerant Campylobacter in different reservoirs at the farm, and the permanence of this pathogen during four consecutive rearing periods. The samples were taken from the same house farm in the downtime period and during the last week of broiler rearing, prior to their slaughter during four consecutive cycles. Different reservoirs as potential sources of Campylobacter were analysed. The prevalence of Campylobacter in vectors was 23% in A. diaperinus larvae, 20% in wild birds, 13% in A. diaperinus adults, and 9% in flies; as regards fomites, the prevalence was 50% in workers' boots, 27% in litter, and 21% in feed, while in broilers it was 80%. Campylobacter jejuni was the most detected species (51%) in the samples analysed. In addition, some Campylobacter genotypes persisted in the house farm throughout consecutive rearing periods, indicating that those strains remain during downtime periods. However, our study could not identify the Campylobacter sources in the downtime periods because all the samples were negative for Campylobacter isolation. In addition, a remarkable finding was the effect of the use of enrofloxacin (as a necessary clinical intervention for flock health) in cycle 3 on the Campylobacter population. No Campylobacter could be isolated after that clinic treatment. Afterwards, we found a greater proportion of C. coli isolates, and the genotypes of those isolates were different from the genotypes found in the previous rearing periods. In conclusion, the effect of the use of enrofloxacin during the rearing period changed the Campylobacter species proportion, and this finding is particularly interesting for further evaluation. Furthermore, more studies should be conducted with the aim of detecting the Campylobacter sources between rearing periods.

Worldwide meta-analysis of the prevalence of Campylobacter in animal food products

The objective of this meta-analysis was to summarize available information on the prevalence of thermotolerant Campylobacter in different animal food products. A number of multilevel random-effect meta-analysis models were fitted to estimate mean prevalence of thermotolerant Campylobacter and to compare them among animal food products (cattle, pigs, broiler, hen, goat, sheep). The mean prevalence of Campylobacter spp. in animal food products was 29.6% (95% CI 27.6%-31%), and the mean prevalence of C. jejuni and C. coli were 19.3% and 9.7%, respectively. The prevalence of Campylobacter spp. was higher in products whose sources were broiler meat (p-estimate = 47.8%; 95% CI 44.9%-50.6%). C. jejuni was mainly observed in broiler meat where prevalence estimate (p-estimate) was 33.7% (95% CI 30.7%-36.8%). On the other hand, C. coli was observed in broiler meat (p-estimate = 14.1%; 95% CI 12.3%-16.1%) and sheep meat (p-estimate = 11.0%; 95% CI 3.6%-29.1%). The animal food products with the lowest prevalence of Campylobacter spp. were milk and dairy products (p-estimate = 3.5%; 95% CI 1.8%-6.5%), eggs (p-estimate = 4.0%; 95% CI 1.4%-10.7%), sausage (p-estimate = 9.4%; 95% CI 3.3%-24.0%), This meta-analysis concluding that C. jejuni is the most prevalent species worldwide and broiler meat is the main contamination source for human. The prevalence of Campylobacter species has public health importance and national authorities must monitor the situation in each country with the aim to establish the appropriate risk management measures.

Comparison of the osteogenic effects between two surface interferential stimulation devices to enhance surgically based spinal fusion

In human medicine, lumbar spinal fusion procedures for chronic degenerative conditions have significant failure rates leading to the formation of pseudoarthroses. Adjunct procedures including the use of electrical stimulation devices have been developed in animal models, and utilized in human clinical cases, in an attempt to reduce the incidence of nonunion. A randomized, controlled study was performed to compare the effects of two surface interferential stimulation devices (SIS) on a rabbit lumbar spinal fusion model. Twenty-five rabbits underwent bilateral intertransverse process arthrodesis at the L2-L3 disc space. The rabbits were divided into five groups: one control group receiving sham stimulation, and four treatment groups receiving interferential stimulation from one of two devices (RS4i at 13.3 mA, RS4i at 15.8 mA, RS4v at 11.6 mA, and RS4v at 14.8 mA). Dual energy X-ray absorptiometry analyses (DXA) were performed and at 2 week intervals to evaluate fusion site bone mineral density. All rabbits were euthanitized at eight weeks and fusion sites were evaluated for biomechanical strength and histomorphometric properties. There was not any difference in bone mineral density between the groups during the eight week test period. The uniaxial tension tests evaluating maximum load to failure, stiffness, and energy absorbed also resulted in no statistical differences between the groups. The RS4i device at 15.8 mA yielded an increased amount of lamellar bone compared to the control group (p = 0.02). The RS4v device at 11.6 mA resulted in less total bone than the control group (p = 0.04).

Impact of lyophilized Lactobacillus salivarius DSPV 001P administration on growth performance, microbial translocation, and gastrointestinal microbiota of broilers reared under low ambient temperature

This study was undertaken with the aim of investigating the effects of dietary supplementation of probiotic strain Lactobacillus salivarius DSPV 001P on growth performance, microbial translocation, and gastrointestinal microbiota of broilers reared under low ambient temperature. Two hundred and forty, one-day-old male Cobb broilers were randomly distributed into two treatment groups, a probiotic group and a control group, with four replicates per treatment and 30 broilers per replicate. The temperature of the broiler house was maintained at 18-22°C during the first three weeks, after which the temperature was at range of 8°C to 12°C. The results showed that probiotic treatment significantly improved body weight of broilers when compared with the control group. After 42days, the weight means were 2905±365.4g and 2724±427.0g, respectively. Although there were no significant differences, dietary inclusion of L. salivarius tended to increase feed intake and to reduce feed conversion ratio during the six-week experimental period. Similarly, supplementation tended to reduce the rate of mortality, with 12 deaths occurring in the probiotic group, and 20 in the control group. However, no differences were observed in intestinal bacterial concentrations of Enterobacteriaceae, E.coli, and lactic acid bacteria in both crop and caecum among treatments. Through our study, it appears that L. salivarius DSPV 001P was non-pathogenic, safe and beneficial to broilers, which implies that it could be a promising feed additive, thus enhancing the growth performance of broilers and improving their health.

Development of cecal-predominant microbiota in broilers during a complete rearing using denaturing gradient gel electrophoresis

Understanding of the intestinal microbiota is crucial to enhance intestinal health and performance parameters in animals. A more exhaustive research of the intestinal microbiota of broilers could be of interest to implement appropriate intervention measures. The aim of the present study was to investigate the development of the predominant cecal microbiota in broilers that were fed a Lactobacillus salivarius DSPV 001P strain during a complete rearing using denaturing gradient gel electrophoresis (DGGE). Bacterial DNA from cecal samples of 24 broilers at different ages were amplified by PCR and analysed by DGGE. A total of 35 DGGE products were excised and sequenced. Distinctive differences in bacterial communities were observed in the caecum as broilers age. At early stages, identified bacteria within the caecum of broilers were predominantly Clostridium-related species. Also, some sequences had the closest match to the genus Escherichia/Shigella. Furthermore, the caecum was a reservoir rich in uncultured bacteria. The major difference observed in our study was an increase of potentially beneficial Lactobacillus at Day 45. These results may be attributed to modulation of the microbiota by the probiotic supplementation. The obtained data could be relevant for future studies related to the influence of the microbiota resulting from probiotic supplementation on the performance and the immunological parameters of broilers.

Quantification of FITC-labelled probiotic Lactobacillus salivarius DSPV 001P during gastrointestinal transit in broilers

The knowledge related to the fate of probiotics in the complex environment of the intestinal microbiota in broilers is just beginning to be elucidated; however, it is not yet well understood. A good method to investigate the mechanisms by which probiotics mediate their effects is to mark probiotic bacteria and trace them. The aim of this research was to develop a new method to estimate in vivo fluorescein isothiocyanate (FITC)-labelled Lactobacillus salivarius DSPV 001P counts during passage through the gastrointestinal tract (GIT) of broilers. Forty-five, 1 d old Cobb broilers were used in this trial. Programmed necropsies were performed 30 min, 6 h, and 12 h after the administration of the probiotic bacterium, and samples of liver, crop, duodenum, caecum, and bursa of fabricius were collected. To determine the spatial and temporal transit of L. salivarius DSPV 001P in broilers, the number of bacteria as well as its respective fluorescent signal produced by FITC were measured. In order to observe the relationship between the variables, a logistic regression analysis was applied. The amount of fluorescence could be used as an indicator of fluorescent probiotic bacteria in the crop and duodenum 30 min after probiotic bacterium supplementation. In addition, the fluorescent signal could be used to estimate bacterial counts in caecum 6 and 12 h after L. salivarius DSPV 001P administration. To the best of our knowledge, this research is the first in vivo trial to employ the bacterial FITC-labelling technique in order to enumerate probiotic bacteria during gastrointestinal transit in broilers.

Single centre experience of hypothermic machine perfusion of kidneys from extended criteria deceased heart-beating donors: a comparative study

INTRODUCTION

Kidneys from extended criteria donors are associated with higher rates of delayed graft function (DGF). Hypothermic machine perfusion (MP) for storage is associated with more favourable outcomes.

METHODS

A retrospective analysis was performed in 93 patients where the kidney was stored using hypothermic MP (LifePort(®)) and compared to an age-matched control group where the kidney was stored in cold static storage (CSS) using University of Wisconsin solution.

RESULTS

Median age was similar in both groups (59.2 years in MP vs 59.9 years in CSS, p = 0.5598). Mean cold storage time was 15.6 h in MP vs 17.9 h in CSS. Post transplant mean serum creatinine was as follows; MP group-144.7 μmol/L at 1 month; 138.3 μmol/L at 3 months and 129.5 μmol/L at 12 months. In the CSS group-163 μmol/L at 1 month; 154.9 μmol/L at 3 months and 140.2 μmol/L at 12 months. There was a statistically significant difference at 1 month (p = 0.0096) and 3 months (p = 0.0236). DGF was defined as the need for haemodialysis within 7 days post transplant. In the MP group, DGF occurred in 17.2 % patients with mean of 6 days (range 1-18). In the CSS group, 25.8 % patients with mean of 8.1 days (range 3-25). One-year graft survival rate was better in the MP group (97.85 vs 96.77 %).

CONCLUSION

Our experience to date recommends the use of hypothermic MP for storage of kidneys from extended criteria deceased heart-beating donors.

Organ donation following the circulatory determination of death (DCD): an audit of donation and outcomes following renal transplantation

Organ Donation following the Circulatory determination of Death was introduced in Beaumont Hospital during 2011. The Intensive Care Society of Ireland formally endorsed a national DCD clinical practice guideline in 2012. This retrospective audit covers a 2-year period during which eleven patients were considered suitable for DCD and where consent was obtained. Nine patients died within the ninety-minute period following the withdrawal of life sustaining therapies and subsequently donated organs (82%). Eighteen kidneys were recovered and seventeen patients received renal transplants--one patient received a nephron-dosing dual renal transplant. Lungs were recovered on two occasions and one patient received a lung transplant. Heart valves were recovered on one occasion. To date sixteen of seventeen recipient patients have functioning renal transplants (94%). In conclusion, this model of deceased donation has proven acceptable to families, nursing and medical staff and the outcomes reported are consistent with international best practice.