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The exact cause of essential hypertension remains unclear. There is evidence to suggest that the development of essential hypertension is causally related to serum calcium levels. This study was designed to assess the status of serum calcium level in patients with essential hypertension and compared with healthy control. The research study was cross-sectional observational in nature. This study was done at the Department of Physiology in Sylhet MAG Osmani Medical College, Sylhet, Bangladesh. The duration of the research period was one year. All the known case of hypertension and newly diagnosed hypertensive patients were selected and compared with age-sex matched apparently healthy individual. Age below 18 years, pregnant women and patients taking supplementary calcium therapy were excluded from this study. Blood pressure was measured by auscultatory method; aneroid sphygmomanometer and standard stethoscope were used. Automated chemistry analyzer Vitrose-350, USA was used to estimate serum calcium level. Standard operating procedure strictly followed. There were 62 hypertensive (both known case of hypertension and newly diagnosed cases) were selected in hypertensive group (Group A) and 62 age-sex matched apparently healthy individuals were selected in normotensive group (Group B). The mean age of hypertensive and normotensive subjects was not statistically significant (p=0.814). There were 27(43.5%) male and 35(56.5%) female in hypertensive group, 32(51.8%) male and 30(48.4%) female in normotensive group. The distribution was statistically not significant (p=0.472). The mean value of the systolic blood pressure (SBP) was 146.45±5.82 mm Hg and the mean value of the diastolic blood pressure (DBP) was 92.90±7.66 mm Hg in hypertensive group. The mean value of the SBP was 112.74±6.88 mm Hg and the mean value of the DBP was 74.52±5.33 mm Hg of the normotensive group. The difference in mean blood pressure (BP) between the two groups was highly significant (p<0.001). The mean value of the serum calcium level was 8.59±0.55 mg/dl in hypertensive group and 9.12±0.93 mg/dl in normotensive group, which was statistically significant (p <0.001) between two groups. Serum calcium was significantly lower in hypertensive group than normotensive group. There was a negative correlation of the serum calcium level with both systolic and diastolic blood pressure.

Staphylococcus aureus is a commensal colonizer of both humans and animals, but also an opportunistic pathogen responsible for a multitude of diseases. In recent years, colonization of pigs by methicillin resistant S. aureus has become a problem with increasing numbers of humans being infected by livestock strains. In S. aureus colonization and virulence factor expression is controlled by the agr quorum sensing system, which responds to and is activated by self-generated, autoinducing peptides (AIPs). AIPs are also produced by coagulase negative staphylococci (CoNS) commonly found as commensals in both humans and animals, and interestingly, some of these inhibit S. aureus agr activity. Here, we have addressed if cross-communication occurs between S. aureus and CoNS strains isolated from pig nares, and if so, how properties such as host factor binding and biofilm formation are affected. From 25 pig nasal swabs we obtained 54 staphylococcal CoNS isolates belonging to 8 different species. Of these, none were able to induce S. aureus agr as monitored by reporter gene fusions to agr regulated genes but a number of agr -inhibiting species were identified including Staphylococcus hyicus , Staphylococcus simulans , Staphylococcus arlettae , Staphylococcus lentus , and Staphylococcus chromogenes . After establishing that the inhibitory activity was mediated via AgrC, the receptor of AIPs, we synthesized selective AIPs to explore their effect on adhesion of S. aureus to fibronectin, a host factor involved in S. aureus colonization. Here, we found that the CoNS AIPs did not affect adhesion of S. aureus except for strain 8325-4. When individual CoNS strains were co-cultured together with S. aureus we observed variable degrees of biofilm formation which did not correlate with agr interactions. Our results show that multiple CoNS species can be isolated from pig nares and that the majority of these produce AIPs that inhibit S. aureus agr . Further they show that the consequences of the interactions between CoNS and S. aureus are complex and highly strain dependent., (Copyright © 2019 Peng, Baldry, Gless, Bojer, Espinosa-Gongora, Baig, Andersen, Olsen and Ingmer.)

Background: Atypical Shigella flexneri Z variant, that agglutinate with E1037 group factor specific monoclonal antisera against Shigella flexneri IV-I but not with other group or type specific antisera, has continuously being isolated in Bangladesh since 1997. Later this serotype has been reported in Indonesia, China and Argentina. Despite being a provisional serotype, continuous isolation of these strains in diverse geographical regions implicated a great necessity to study the overall characteristics of these strains. Therefore, we extensively characterized S. flexneri Z strains using various phenotypic and molecular tools., Method: Of 3569 S. flexneri isolated between 1997 and 2015, 95 strains were identified as S. flexneri Z using a panel of polyvalent absorbed antisera and monoclonal antisera of S. flexneri (MASF). Of them, randomly selected 65 strains were molecular O-serotyped using multiplex PCR and characterized using different phenotypic and molecular techniques (i.e.biotyping, plasmid profile, virulence marker and PFGE) to determine relationship with other subserotypes of S. flexneri., Results: All these atypical S. flexneri Z strains were agglutinated with MASF B and IV-I antisera. Concordantly, these strains were positive to opt-gene, responsible for MASF IV-I sero-positive phenotype. However, molecular O-serotyping of all 65 strains could not differentiate between Z and Yb giving similar amplification products (wzx1-5 and opt). Contrarily, MASF based serotypic scheme distinguished among Z and Yb as well as Ya. All these S. flexneri Z showed typical biochemical reaction of S. flexneri, harboured a 140 MDa virulence plasmid and virulence markers namely ipaH, ial, sen, sigA and sepA genes. Along with the virulence plasmid, small plasmids (2.6, 1.8 and 1.6 MDa) were present as core plasmid. Moreover, a middle ranged plasmid and a 4.0 MDa sized plasmid were observed in 65% and 20% strains, respectively. Analysis of PFGE on XbaI-digested chromosomal DNA of Bangladeshi strains showed that S. flexneri Z had a close relatedness with Ya and Yb but completely different than the strains of Xa, Xb, 2a and 2b. This observation was found to be unequivocal while the overall result of biotyping, plasmid profile, and virulence factors was compared. Therefore, we conclude that these atypical serotype Z isolated in Bangladesh had a clonal relationship with Ya and Yb of Bangladesh and the opt gene played an important role in serotypic switching among them. Current serotyping scheme of S. flexneri strains fails to place many such atypical strains (1c, 1c+6, 1d, type 4, and 4c) including S. flexneri Z isolated from different parts of the world. Therefore, an updated serotyping scheme for identification of subserotypes of S. flexneri has been proposed to avoid multiple naming of the same subserotype having similar agglutination pattern., Competing Interests: The authors have declared that no competing interests exist.

To examine rates of Shigella infections in household contacts of pediatric shigellosis patients, we followed contacts and controls prospectively for 1 week after the index patient obtained care. Household contacts of patients were 44 times more likely to develop a Shigella infection than were control contacts (odds ratio 44.7, 95% CI 5.5-361.6); 29 (94%) household contacts of shigellosis patients were infected with the same species and serotype as the index patient's. Pulsed-field gel electrophoresis showed that 14 (88%) of 16 with infected contacts had strains that were indistinguishable from or closely related to the index patient's strain. Latrine area fly counts were higher in patient households compared with control households, and 2 patient household water samples were positive for Shigella. We show high susceptibility of household contacts of shigellosis patients to Shigella infections and found environmental risk factors to be targeted in future interventions.