Isolation and characterization of anti-Salmonella lactic acid bacteria from the porcine gastrointestinal tract.

AIMS: To identify lactic acid bacteria (LAB) of porcine intestinal origin with anti-Salmonella activity. METHODS AND RESULTS: Samples were obtained from pig faeces and caeca and screened for the presence of anti-Salmonella LAB. The 11 most promising isolates were identified as belonging to the genera Lactobacillus and Pediococcus. The LAB exhibited large variation in their ability to survive in simulated gastric juice at pH 1.85. While Lactobacillus johnsonii species survived at levels of 80% for up to 30 min, Lactobacillus pentosus species declined to <0.001% in that time. All isolates tolerated porcine bile at a concentration of 0.3% (w/v), with some isolates capable of growth in the presence of up to 5% (w/v) bile. The ability of the LAB isolates to prevent Salmonella invasion of intestinal epithelial HT-29 cells varied, with reductions of between 30% (Lact. pentosus) and 80% (Lactobacillus murinus spp.) observed. CONCLUSIONS: LAB of porcine origin were observed to survive simulated passage through the GIT and inhibit growth of Salmonella and its invasion of the intestinal epithelium. SIGNIFICANCE AND IMPACT OF THE STUDY: The data demonstrate that some porcine intestinal LAB isolates may offer potential as probiotics for the reduction of Salmonella carriage in pigs.

Molecular detection of Candida krusei contamination in fruit juice using the citrate synthase gene cs1 and a potential role for this gene in the adaptive response to acetic acid.

AIMS: To develop a reverse transcription-polymerase chain reaction (RT-PCR) assay to detect viable Candida krusei contaminations and examine the potential role of the citrate synthase (cs1) gene in adaptation to acetic acid. METHODS AND RESULTS: Fruit juice artificially contaminated with C. krusei cells was heat treated to inactivate the yeast cells, after which the improved ability of the RT-PCR over the PCR assay, through the amplification of the cs1 gene, to differentiate viable contaminations was shown. The sensitivity of the detection assay was 6 x 104 CFU ml-1. RT-PCR and densitometric analysis of the cs1 gene throughout the process of adaptation to acetic acid highlighted a potential role for the gene in the yeast's adaptive response. CONCLUSIONS: The RT-PCR assay through the targeting of the cs1 gene proved to be a specific, sensitive and direct method for the identification of a C. krusei contamination in a food environment. The cs1 gene was shown to play a potential role in the adaptation of the culture to the weak-acid preservative acetic acid. SIGNIFICANCE AND IMPORTANCE OF THE STUDY: The development of a direct, sensitive and specific identification assay for C. krusei from a food environment and understanding the mechanism employed in adapting to a preservative challenge, represent important tools to the food industry in attempting to limit spoilage by this important food spoilage yeast.

Trauma pneumonectomy revisited: the role of simultaneously stapled pneumonectomy.

OBJECTIVE: The aim of this study was to compare simultaneously stapled pneumonectomy (SSP) with individual ligation (IND) as a method for performing urgent pneumonectomy (Py) for trauma. METHODS: Twelve patients who required Py were reviewed. SSP was performed in nine cases and IND in three cases. The two groups had statistically similar injury severity scores, presenting systolic blood pressures, and Trauma and Injury Severity Score derived probabilities of survival. An animal model of Py was developed, in which seven animals underwent SSP and seven underwent IND methods. Burst pressures of the pulmonary artery and bronchus were calculated after 14 days. RESULTS: There were no differences noted in survival rates between SSP (5 (56%)) and IND (1 (33%)), nor in incidence of bronchopleural fistula. The SSP group had a significantly shorter operative time compared with that of IND (88.9 +/- 14.3 minutes vs 213 +/- 57.8 minutes, respectively, p - 0.01). The animal study revealed no difference in burst pressures of the bronchus (SSP = 662.9 +/- 169.9 mm Hg vs. IND = 591.4 +/- 193.2 mm Hg, p = 0.752) or of the pulmonary artery (SSP = 554.3 +/- 195.1 mm Hg vs. IND = 477.7 +/- 247.5 mm Hg, p = 0.529). CONCLUSION: Survival after pulmonary injuries that require Py depends upon the rapidity of hilar control and of the procedures itself. Simultaneously stapled pneumonectomy is an effective and rapid method of dealing with such rare injuries.