Comparison of virulence gene profiles of Escherichia coli strains isolated from healthy and diarrheic swine

A combination of uni- and multiplex PCR assays targeting 58 virulence genes (VGs) associated with Escherichia coli strains causing intestinal and extraintestinal disease in humans and other mammals was used to analyze the VG repertoire of 23 commensal E. coli isolates from healthy pigs and 52 clinical isolates associated with porcine neonatal diarrhea (ND) and postweaning diarrhea (PWD). The relationship between the presence and absence of VGs was interrogated using three statistical methods. According to the generalized linear model, 17 of 58 VGs were found to be significant (P < 0.05) in distinguishing between commensal and clinical isolates. Nine of the 17 genes represented by iha, hlyA, aidA, east1, aah, fimH, iroN(E. coli), traT, and saa have not been previously identified as important VGs in clinical porcine isolates in Australia. The remaining eight VGs code for fimbriae (F4, F5, F18, and F41) and toxins (STa, STb, LT, and Stx2), normally associated with porcine enterotoxigenic E. coli. Agglomerative hierarchical algorithm analysis grouped E. coli strains into subclusters based primarily on their serogroup. Multivariate analyses of clonal relationships based on the 17 VGs were collapsed into two-dimensional space by principal coordinate analysis. PWD clones were distributed in two quadrants, separated from ND and commensal clones, which tended to cluster within one quadrant. Clonal subclusters within quadrants were highly correlated with serogroups. These methods of analysis provide different perspectives in our attempts to understand how commensal and clinical porcine enterotoxigenic E. coli strains have evolved and are engaged in the dynamic process of losing or acquiring VGs within the pig population.     

Dissemination of Fluoroquinolone-Resistant Campylobacter spp. within an Integrated Commercial Poultry Production System

While characterizing the intestinal bacterial community of broiler chickens, we detected -proteobacterial DNA in the ilea of 3-day-old commercial broiler chicks (J. Lu, U. Idris, B. Harmon, C. Hofacre, J. J. Maurer, and M. D. Lee, Appl. Environ. Microbiol. 69:6816-6824, 2003). The sequences exhibited high levels of similarity to Campylobacter jejuni and Campylobacter coli sequences, suggesting that chickens can carry Campylobacter at a very young age. Campylobacter sp. was detected by PCR in all samples collected from the ilea of chicks that were 3 to 49 days old; however, it was detected only in the cecal contents of chickens that were at least 21 days old. In order to determine whether the presence of Campylobacter DNA in young chicks was due to ingestion of the bacteria in food or water, we obtained commercial broiler hatching eggs, which were incubated in a research facility until the chicks hatched. DNA sequencing of the amplicons resulting from Campylobacter-specific 16S PCR performed with the ileal, cecal, and yolk contents of the day-of-hatching chicks revealed that Campylobacter DNA was present before the chicks consumed food or water. The 16S rRNA sequences exhibited 99% similarity to C. jejuni and C. coli sequences and 95 to 98% similarity to sequences of other thermophilic Campylobacter species, such as C. lari and C. upsaliensis. The presence of C. coli DNA was detected by specific PCR in the samples from chicks obtained from a commercial hatchery; however, no Campylobacter was detected by culturing. In order to determine whether the same strains of bacteria were present in multiple levels of the integrator, we cultured Campylobacter sp. from a flock of broiler breeders and their 6-week-old progeny that resided on a commercial broiler farm. The broiler breeders had been given fluoroquinolone antibiotics, and we sought to determine whether the same fluoroquinolone-resistant strain was present in their progeny. The isolates were typed by pulsed-field gel electrophoresis, which confirmed that the parental and progeny flocks contained the same strain of fluoroquinolone-resistant C. coli. These data indicate that resistant C. coli can be present in multiple levels of an integrated poultry system and demonstrated that molecular techniques or more sensitive culture methods may be necessary to detect early colonization by Campylobacter in broiler chicks.     

Male‐killer dynamics in Danaus chrysippus (L.) (Lepidoptera: Nymphalidae) in East Africa

Within certain regions in East Africa, the butterfly Danaus chrysippus (L.) shows female‐biased population sex ratio, because of the production by some females of all‐female broods, as a result of infection by maternally inherited, male‐killing bacterium of the genus Spiroplasma. In this study, we describe a 3‐year field survey for the population dynamics of the male‐killing Spiroplasma in D. chrysippus in four independent localities, namely Uganda, Ghana, Sudan and Madagascar. The prevalence of the bacterium was found to show extensive variations at multiple scales among different sites, in various countries, seasons and years. A novel, selection‐based hypothesis was suggested to explain the high variability of male‐killer prevalence over space and time, based on the existence of an adaptive link between larval food‐plant density and the magnitude of resource reallocation fitness advantage for the male‐killer.     

GPCR-MPredictor: multi-level prediction of G protein-coupled receptors using genetic ensemble

G protein-coupled receptors (GPCRs) are transmembrane proteins, which transduce signals from extracellular ligands to intracellular G protein. Automatic classification of GPCRs can provide important information for the development of novel drugs in pharmaceutical industry. In this paper, we propose an evolutionary approach, GPCR-MPredictor, which combines individual classifiers for predicting GPCRs. GPCR-MPredictor is a web predictor that can efficiently predict GPCRs at five levels. The first level determines whether a protein sequence is a GPCR or a non-GPCR. If the predicted sequence is a GPCR, then it is further classified into family, subfamily, sub-subfamily, and subtype levels. In this work, our aim is to analyze the discriminative power of different feature extraction and classification strategies in case of GPCRs prediction and then to use an evolutionary ensemble approach for enhanced prediction performance. Features are extracted using amino acid composition, pseudo amino acid composition, and dipeptide composition of protein sequences. Different classification approaches, such as k-nearest neighbor (KNN), support vector machine (SVM), probabilistic neural networks (PNN), J48, Adaboost, and Naives Bayes, have been used to classify GPCRs. The proposed hierarchical GA-based ensemble classifier exploits the prediction results of SVM, KNN, PNN, and J48 at each level. The GA-based ensemble yields an accuracy of 99.75, 92.45, 87.80, 83.57, and 96.17% at the five levels, on the first dataset. We further perform predictions on a dataset consisting of 8,000 GPCRs at the family, subfamily, and sub-subfamily level, and on two other datasets of 365 and 167 GPCRs at the second and fourth levels, respectively. In comparison with the existing methods, the results demonstrate the effectiveness of our proposed GPCR-MPredictor in classifying GPCRs families. It is accessible at .     

Benzimidazole bearing oxadiazole and triazolo-thiadiazoles nucleus: Design and synthesis as anticancer agents

Two new series of benzimidazole bearing oxadiazole[1-(1H-benzo[d]imidazol-2-yl)-3-(5-substituted-1,3,4-oxadiazol-2-yl)propan-1-ones (4a-l)] and triazolo-thiadiazoles[1-(1H-benzo[d]imidazol-2-yl)-3-(6-(substituted)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-3-yl)propan-1-one (7a-e)] have been synthesized successfully from4-(1H-benzo[d]imidazol-2-yl)-4-oxobutanehydrazide (3) with an aim to produce promising anticancer agents. In vitro anticancer activities of synthesized compounds were screened at the National Cancer Institute (NCI), USA, according to their applied protocol against full NCI 60 human cell lines panel; results showed good to remarkable anticancer activity. Among them, compound (4j, NCS: 761980) exhibited significant growth inhibition and further screened at 10-fold dilutions of five different concentrations (0.01, 0.1, 1, 10 and 100μM) with GI(50) values ranging from 0.49 to 48.0μM and found superior for the non-small cell lung cancer cell lines like HOP-92 (GI(50) 0.49, TGI 19.9,LC(50) >100 and Log(10)GI(50) -6.30, Log(10)TGI -4.70, Log(10)LC(50) >-4.00).     

Cineradiography of monkey lip-smacking reveals putative precursors of speech dynamics

A key feature of speech is its stereotypical 5 Hz rhythm. One theory posits that this rhythm evolved through the modification of rhythmic facial movements in ancestral primates. If the hypothesis has any validity, then a comparative approach may shed some light. We tested this idea by using cineradiography (X-ray movies) to characterize and quantify the internal dynamics of the macaque monkey vocal tract during lip-smacking (a rhythmic facial expression) versus chewing. Previous human studies showed that speech movements are faster than chewing movements, and the functional coordination between vocal tract structures is different between the two behaviors. If rhythmic speech evolved through a rhythmic ancestral facial movement, then one hypothesis is that monkey lip-smacking versus chewing should also exhibit these differences. We found that the lips, tongue, and hyoid move with a speech-like 5 Hz rhythm during lip-smacking, but not during chewing. Most importantly, the functional coordination between these structures was distinct for each behavior. These data provide empirical support for the idea that the human speech rhythm evolved from the rhythmic facial expressions of ancestral primates.     

Cockayne syndrome-xeroderma pigmentosum complex with demyelination: A rare association

Xeroderma pigmentosum-Cockayne syndrome (XP-CS) includes facial freckling and early skin cancers typical of XP and some features typical of CS, such as mental retardation, spasticity, short stature, and hypogonadism. XP-CS does not include skeletal involvement, the facial phenotype of CS, or CNS demyelination and calcifications. We present a rare patient whose genome probably harbored a specific combination of mutations producing a rare double syndrome of XP-CS, with facial phenotype of CS, and CNS demyelination.     

Expression and identification of folate-sensitive fragile sites in British Suffolk sheep (<Emphasis Type="Italic">Ovis aries</Emphasis>)

An investigation to understand the dynamics and biological significance of fragile site expression, and identification of 5-fluorodeoxyuridine (FUdR) induced chromosomal gaps/breaks, were carried out in an experimental flock of 45 Suffolk sheep. The statistical comparison revealed, highly significant variation in the frequency of chromosomal fragile site expression between control and FUdR cultures. Mean (± S.D.) values for cells with gaps and breaks, or aberrant cell count (AC), and the number of aberrations (NoA) per animal were 2.02 ± 0.34, 2.42 ± 0.48, 13.26 ± 0.85 and 21.87 ± 1.88 (P < 0.01) in control and FUdR cultures, respectively. The comparison of age revealed nonsignificant variation between control and FUdR cultures. The G-band analysis of fragile site data revealed gaps in 29 autosomal and two X-chromosomal bands in the control cultures, whereas FUdR treated cultures scored 78 unstable bands in autosomes of which 56 were significantly fragile. X-chromosomes expressed breaks and gaps in six G-negative bands and five of them (Xq13, Xq15, Xq17, Xq24 and Xq26) were significantly fragile. The distribution comparison of autosomal fragile sites between sex groups did not reveal any significant variation. Female X-chromosomes were significantly more fragile than the male X-chromosomes. The distribution comparison for age groups (lambs versus adults) revealed significantly higher number of fragile bands in adults. Comparison of published data on reciprocal translocations in sheep with the fragile-site data obtained in this study indicated that the break sites of both phenomena were correlated. Similarities were also found between fragile sites and breakpoints of evolutionary significance in family Bovidae.