Iron and virulence in Stenotrophomonas maltophilia: all we know so far

Stenotrophomonas maltophilia is a multi-drug-resistant global opportunistic nosocomial pathogen, which possesses a huge number of virulence factors and antibiotics resistance characteristics. Iron has a crucial contribution toward growth and development, cell growth and proliferation, and pathogenicity. The bacterium found to acquire iron for its cellular process through the expression of two iron acquisition systems. Two distinct pathways for iron acquisition are encoded by the S. maltophilia genome-a siderophore-and heme-mediated iron uptake system. The entAFDBEC operon directs the production of the enterobactin siderophore of catecholate in nature, while heme uptake relies on hgbBC and potentially hmuRSTUV operon. Fur and sigma factors are regulators of S. maltophilia under iron-limited condition. Iron potentially act as a signal which plays an important role in biofilm formation, extracellular polymeric substances (EPS), extracellular enzymes production, oxidative stress response, diffusible signal factor (DSF) and siderophore production in S. maltophilia. This review summarizes the current knowledge of iron acquisition in S. maltophilia and the critical role of iron in relation to its pathogenicity

The 'checkmate' for iron between human host and invading bacteria: chess game analogy

Iron is an essential nutrient for all living organisms with critical roles in many biological processes. The mammalian host maintains the iron requirements by dietary intake, while the invading pathogenic bacteria compete with the host to obtain those absorbed irons. In order to limit the iron uptake by the bacteria, the human host employs numerous iron binding proteins and withholding defense mechanisms that capture iron from the microbial invaders. To counteract, the bacteria cope with the iron limitation imposed by the host by expressing various iron acquisition systems, allowing them to achieve effective iron homeostasis. The armamentarium used by the human host and invading bacteria, leads to the dilemma of who wins the ultimate war for iron

Effect of Chloramphenicol on Rabbit Doe Fertility and Prenatal Development

Chloramphenicol (CP) is a synthetic antibiotic with large spectrum, mostly used in human and veterinary medicine to fight against diverse infections. In the present study the effects of this antibiotic on some does reproductive parameters were evaluated on 24 nulliparous, sexually mature female (6 months). The animals were divided into 4 groups of 6 does each, comparable in terms of body weight. To each group was randomly attributed by gavage 25, 50 and 75mg of CP/kg of body weight 30 days before mating (6 females for 1 male) and during the whole gestation period. After sacrifice of the does on the 28th day post-coitum, the organs (ovaries, liver, and kidneys) and fetus were collected and were examined to detect eventual anomalies. The main results showed a non-significant increase (P>0.05) of the relative weight of the liver and kidneys and a non-significant decrease (P>0.05) of that of the ovaries with increase in the dose of CP. No abortions were registered no matter the dose of CP. Gestation index, the rate of fetal mortality and of fetal viability were not significantly affected by the dose of CP used. A decreasing (P0.05) of the average weight of the fetus and their body measurement, the number of corpus luteum and the sex-ratio (M/F) were registered from treated animals in relation to the control animals. A dose-dependent increase (P<0.05) of number of pre and post-implantation resorptions were noted. The only anomaly registered was the insufficient fusion of the cranial bones at the dose 50 and 75mg/kg of CP. A significant decrease (P<0.05) of the level of proteins in the serum and ovaries were noted in animals treated in relation to those of the control group. It was concluded that CP administered at doses of 25, 50 and 75 mg/kg bw to pre and post-coital rabbit does, negatively affects fertility but has no significant teratogenic effects. Its use should therefore be limited or prohibited in husbandry

Production of the virus-like particles of nipah virus matrix protein in Pichia pastoris as diagnostic reagents

The matrix (M) protein of Nipah virus (NiV) is a peripheral protein that plays a vital role in the envelopment of nucleocapsid protein and acts as a bridge between the viral surface and the nucleocapsid proteins. The M protein is also proven to play an important role in production of virus-like particles (VLPs) and is essential for assembly and budding of NiV particles. The recombinant M protein produced in Escherichia coli assembled into VLPs in the absence of the viral surface proteins. However, the E. coli produced VLPs are smaller than the native virus particles. Therefore, the aims of this study were to produce NiV M protein in Pichia pastoris, to examine the structure of the VLPs formed, and to assess the potential of the VLPs as a diagnostic reagent. The M protein was successfully expressed in P. pastoris and was detected with anti-myc antibody using Western blotting. The VLPs formed by the recombinant M protein were purified with sucrose density gradient ultracentrifugation, high-performance liquid chromatography (HPLC), and Immobilized Metal Affinity Chromatography (IMAC). Immunogold staining and transmission electron microscopy confirmed that the M protein assembled into VLPs as large as 200 nm. ELISA revealed that the NiV M protein produced in P. pastoris reacted strongly with positive NiV sera demonstrating its potential as a diagnostic reagent

La sonnette du diable

Conjunt de particel·les dels següents instruments: 1r violí, 2n violí, viola, contrabaix, flauta, 1r clarinet, 2n clarinet, trompes o saxhorn, 1a corneta, 2a corneta, 1r trombó, 2n trombó, 3r trombó baix, figle, bombo i tamborConté catàleg d'altres partitures de l'editorialQuadrill

Molecular characterization of pathogenic Leptospira sp. in small mammals captured from the human leptospirosis suspected areas of Selangor state, Malaysia

Leptospirosis is caused by the spirochetal bacterium Leptospira of which rodents are considered the most important reservoir. This study aims to determine and characterize virulent Leptospira species among rodents and small mammals found in human settlements and recreational spots within the Hulu Langat and Gombak districts of Selangor, Malaysia; regions that frequently report probable human leptospirosis cases. Molecular analysis revealed an overall Leptospira detection rate of 14.3% among the 266 small mammals captured, and the human settlements were found to have the highest number of isolates (15.1%), followed by recreational sites (14.5%). The molecular characterization conducted based on the lipL32, secY genes and MLST revealed that the strains belonged to four different species, including; Leptospira interrogans (29; 76.3%; ST50, ST238, ST243), L. kirschneri (5; 13.15%; ST110), L. borgpetersenii (3; 8%; ST143) and L. weilii (1; 2.63%; ST242). The study revealed genotypes of circulating strains among small mammals in Malaysia, which include Leptospira locus ST110 L. kirschneri, ST 50 L. interrogans, ST143 L. borgpetersenii and ST242 L. weilii. Among the small mammals studied, 17/105 (16.2%) Rattus norvegicus, 7/59 (11.9%) of Rattus rattus, 5/24 (20.8%) of Maxomys whiteheadi, 4/18 (22.2%) of Sundamys muelleri, 2/22 (9%), Tupaia gliss, 2/16 (12.5%) Rattus tiomanicus and 1/4 (25%) of Suncus murinus carried pathogenic leptospires. The data from the present study may imply that, in addition to rodents, other small mammals also serve as maintenance hosts for Leptospira. Hence, much remains unknown about Leptospira maintenance hosts, and there is need for further investigation to ascertain the prevailing serovars of pathogenic Leptospira in Malaysia. This will assist in the development of efficient diagnostic assays with improved microscopic agglutination test (MAT) panels, and in the implementation of suitable prevention and control measures

Les filles de marbre

Conjunt de particel·les del següents instruments: 1r violí, 2n violí, viola, violoncel i contrabaix, flauta o flageolet, 1r clarinet, 2n clarinet, trompes o saxhorn, 1a corneta, 2a corneta, 1r i 2n trombons, trombó baix, figle, tambor i bomboQuadrilla. Música d'Édouard Montaubry i arranjaments de Narcisse Joseph Bousque

Alteration of the Gut Microbiome in Normal and Overweight School Children from Selangor with \u3ci\u3eLactobacillus\u3c/i\u3e Fermented Milk Administration

Childhood obesity is a serious public health problem worldwide. Perturbations in the gut microbiota composition have been associated with the development of obesity in both children and adults. Probiotics, on the other hand, are proven to restore the composition of the gut microbiome which helps reduce the development of obesity. However, data on the effect of probiotics on gut microbiota and its association with childhood obesity is limited. This study aims to determine the effect of probiotics supplement intervention on gut microbiota profiles in obese and normal-weight children. A total of 37 children, 17 normal weight, and 20 overweight school children from a government school in Selangor were selected to participate in this study. Participants were further divided into intervention and control groups. The intervention groups received daily probiotic drinks while the control groups continued eating their typical diet. Fecal samples were collected from the participants for DNA extraction. The hypervariable V3 and V4 regions of 16S rRNA gene were amplified and sequenced using the Illumina MiSeq platform. No significant differences in alpha diversity were observed between normal weight and obese children in terms of the Shannon Index for evenness or species richness. However, a higher intervention effect on alpha diversity was observed among normal-weight participants compared to obese. The participants’ microbiome was found to fluctuate throughout the study. Analysis of the taxa at species level showed an increase in Bacteroides ovatus among the normal weight cohort. Genus-level comparison revealed a rise in genus Lachnospira and Ruminococcus in the overweight participants after intervention, compared to the normal-weight participants. The probiotics intervention causes an alteration in gut microbiota composition in both normal and overweight children. Though the association could not be defined statistically, this study has provided an improved understanding of the intervention effect of probiotics on gut microbiome dysbiosis in an underrepresented population

Production of long helical capsid of Nipah virus by Pichia pastoris.

The nucleocapsid (N) protein of Nipah virus (NiV) produced in a recombinant host can replace the use of inactivated virus as a diagnostic reagent because it is safer and affordable. The aim of this study was to express the N protein in Pichia pastoris. The N gene of NiV was cloned into the yeast expression vector, pPICZ B and expressed in P. pastoris. The recombinant N protein of NiV was purified using sucrose density gradient ultracentrifugation and was confirmed with Western blotting using rabbit anti-N antibody. The P. pastoris expressed N protein self-assembled into helical structures as large as 1.5 μm as shown in an electron micrograph. ELISA analysis performed with the swine sera obtained during the viral outbreak proved that the recombinant N protein to be highly antigenic. The NiV N protein produced in P. pastoris serves as an alternative to the recombinant N protein produced in Escherichia coli

Etude Des Determinants Socioeconomiques Et Techniques De La Psciculture Extensive En Cote D’ivoire

The contribution of fish farming is relatively low in the national consumption of fish products. Yet the country has a significant socio-natural potential, which well valued can reduce fish imports and enhance food security. This study, based on a survey conducted in the two main areas of extensive fish farming (Central West and Southwest), was to analyze the technical and socioeconomic determinants of family fish farming to support the dynamic development of this activity. The results showed that 98% of fish farmers are men of 51 to 60 years old. Most of them are illiterate practicing agriculture as their main activity. Farming infrastructure are usually composed of dams ponds (90%) of 0.25-1.5 ha, and ponds of 0.1 ha. Water was provided either by river (95%) or groundwater (5%). On average most farms are of mall size (3 ha) and were acquired by purchasing lands. Fish farmers mainly practiced mixed farming of Tilapia (Oreochromis niloticus) and Heterotis (Heterotis niloticus). In 60% of the cases, fish farming is associated with rice cultivation practiced in the shallows. Fish were mainly fed with rice bran. An important number of farmers (72%) practiced sexing of in order to improve their yields. Furthermore, 60% of them have a lower production to 6 tons per year, and fish were old between 1500 and 2000 CFA (1 FCFA=0,0014 euros) per kg leading to an average annual income of less than 5 million CFA francs