Outer Membrane Protein F Is Involved in Biofilm Formation, Virulence and Antibiotic Resistance in Cronobacter sakazakii

In some Gram-negative bacteria, ompF encodes outer membrane protein F (OmpF), which is a cation-selective porin and is responsible for the passive transport of small molecules across the outer membrane. However, there are few reports about the functions of this gene in Cronobacter sakazakii. To investigate the role of ompF in detail, an ompF disruption strain (ΔompF) and a complementation strain (cpompF) were successfully obtained. We find that OmpF can affect the ability of biofilm formation in C. sakazakii. In addition, the variations in biofilm composition of C. sakazakii were examined using Raman spectroscopy analyses caused by knocking out ompF, and the result indicated that the levels of certain biofilm components, including lipopolysaccharide (LPS), were significantly decreased in the mutant (ΔompF). Then, SDS-PAGE was used to further analyze the LPS content, and the result showed that the LPS levels were significantly reduced in the absence of ompF. Therefore, we conclude that OmpF affects biofilm formation in C. sakazakii by reducing the amount of LPS. Furthermore, the ΔompF mutant showed decreased (2.7-fold) adhesion to and invasion of HCT-8 cells. In an antibiotic susceptibility analysis, the ΔompF mutant showed significantly smaller inhibition zones than the WT, indicating that OmpF had a positive effect on the influx of antibiotics into the cells. In summary, ompF plays a positive regulatory role in the biofilm formation and adhesion/invasion, which is achieved by regulating the amount of LPS, but is a negative regulator of antibiotic resistance in C. sakazakii.

Mammary Development in Gilts at One Week Postnatal Is Related to Plasma Lysine Concentration at 24 h after Birth, but Not Colostrum Dose

Perinatal nutrition affects future milk production. The number of mammary epithelial cells affect milk production capacity. Therefore, it was hypothesized that the level of colostrum intake affects the proliferation rate and the total number of mammary epithelial cells in the gland. The ratio of newly synthesized protein to newly synthesized DNA reflects the relative amount of cellular differentiation to cell division. The study objective was to determine the relationship between the level of colostrum intake and 24 h-level of circulating amino acid, glucose and insulin with mammary parenchyma histological features, cell division and protein synthesis over the first week postnatal. One of two standardized doses of a homogenate colostrum sample, 10% (n = 8) and 20% (n = 8) of birth bodyweight, was fed to gilts over the first 24 h postnatal. Gilts were administered deuterium oxide immediately after birth and daily to label newly synthesized DNA and proteins. Gilts were euthanized on postnatal day seven, and DNA and protein were isolated from mammary parenchyma. DNA and protein fractional synthesis (f) and fractional synthetic rate (FSR) were calculated using mass isotopomer distribution analysis. The ratio of protein f and FSR to DNA f and FSR were calculated and used to indicate the relative amounts of differentiation to cell division. Mammary morphological development was also analyzed by measuring the parenchymal epithelial area and the stromal and epithelial proliferation index on postnatal day seven. Colostrum dose was not related to any of the variables used to evaluate mammary development. However, plasma lysine levels at 24 h postnatal were positively related to average daily gain (ADG; r = 0.54, p = 0.05), DNA f (r = 0.57; p = 0.03) and DNA FSR (r = 0.57; p = 0.03) in mammary parenchyma. Plasma lysine was inversely related to the ratio of protein to DNA f and FSR (r = −0.56; p = 0.04). ADG was related to the parenchymal epithelial area and DNA and protein f and FSR (p < 0.05). These relationships support the idea that the nutritional environment affects early mammary development and that higher lysine levels in the perinatal period favored a greater degree of cell division versus differentiation in mammary of neonatal pigs and thus, warrant further investigations.

Over-expression of centromere protein F in human endometrial cancer.

Gynecologic cancers including cancers of the endometrium are a clinical problem (1-4). We mined published microarray data (5, 6) to discover genes associated with endometrial cancers by comparing transcriptomes of the normal endometrium and endometrial tumors from humans. We identified centromere protein F, encoded by CENPF, as among the most differentially expressed genes, transcriptome-wide, in cancers of the endometrium. CENPF was expressed at significantly higher levels in endometrial tumor tissues as compared to the endometrium. Importantly, primary tumor expression of CENPF was correlated with overall survival in patients with endometrial cancer. CENPF may be a molecule of interest in understanding the etiology or progression of human endometrial cancer.

Differential expression of centromere protein F in cancers of the breast.

Breast cancer affects women at relatively high frequency (1). We mined published microarray datasets (2, 3) to determine in an unbiased fashion and at the systems level genes most differentially expressed in the primary tumors of patients with breast cancer. We report here significant differential expression of the gene encoding the centromere protein F, CENPF, when comparing primary tumors of the breast to the tissue of origin, the normal breast. CENPF was also differentially expressed in the tumor cells of patients with triple negative breast cancer. CENPF mRNA was present at significantly higher quantities in tumors of the breast as compared to normal breast tissue. Analysis of human survival data revealed that expression of CENPF in primary tumors of the breast was correlated with overall survival in patients with basal, luminal A, and luminal B subtype cancer, but in a contrary manner. CENPF may be of relevance to initiation, maintenance or progression of cancers of the female breast.

Analisis Filogeni Virus Newcastle Disease Isolat Bali Tahun 2013 Sampai 2014 Berdasarkan Sekuen Daerah Pemotongan Protein Fusion

Newcastle disease (ND) merupakan penyakit kontagius yang disebabkan virus Avian paramyxovirus serotype 1 yang menginfeksi bangsa unggas. Penelitian ini bertujuan untuk menganalisis pohon filogeni berdasarkan sekuan gen daerah pemotonan protein fusion dari virus ND pada peternakan ayam di provinsi Bali dari tahun 2013 sampai 2014. Sebanyak empat isolat virus dari kasus ayam sakit/mati yang dicurigai terinfeksi oleh virus Newcastle disease. Sekuen potongan gen F disejajarkan dan dianalisis dengan program MEGA5. Analisis sekuen asam amino daerah pemotongan protein F keempat isolat memiliki sekuen 112R-R-Q-K-R-F117 dan dilanjutkan dengan analisis pohom filogeni yang menunjukan bahwa keempat isolat merupakan virus Newcastle disease yang virulen. Penelitian ini menunjukan bahwa keempat isolat lapang Bali tahun 2013 sampai 2014 masuk ke dalam kelompok virus Newcastle disease genotipe VII.